Most of the houses we live in now will still be in use for decades to come – and millions of UK homes need to be retrofitted to radically improve their energy efficiency as we transition to zero carbon. Effective insulation is a vital part of this, but the materials we choose can make a big difference.

Types of insulation materials

There are basically three different types of insulation material:

1. Organic – those derived from natural vegetation or similar renewable sources, which tend to require a low energy use in manufacture (a low ‘embodied energy’). Examples are sheep’s wool, cellulose, cork, wood fibre, and hemp. Some are recycled from waste paper or textiles.
2. Inorganic – derived from naturally occurring minerals which are nonrenewable but plentiful at source. Likely to have a higher embodied energy than organic materials. Examples are mineral/glass fibre, perlite and vermiculite (from volcanic rock) and rigid foamed glass. Some of these could be from recycled sources.
3. Fossil organic – derived by chemical processes from fossilised vegetation (oil) – a finite resource. Fossil organic insulation materials such as expanded polystyrene and polyisocyanurate or phenolic foam are highly processed, resulting in a high embodied energy than either of the other types above.

Which is best?

If possible it is better to choose insulation materials that have not been heavily processed as this will reduce the carbon footprint and environmental impact of your home. The breathability of insulation materials is particularly important in older buildings (with solid walls). But as long as issues like breathability and damp risks are addressed, inorganic or fossil organic materials are better than nothing at all, because insulating your home will lead to energy and pollution savings. Many grant funded schemes may offer only a limited choice of materials, and there is not an organic insulation material suitable for cavity wall insulation.

The costs of insulation materials vary quite a bit, so do check what the current options are for your project. Some types of plastic foam can be quite expensive, and natural fibre insulations are getting cheaper as companies start manufacturing these on a larger scale within the UK.

If doing the work yourself, think also about the ease of installation when making a choice. Fluffy insulation is good for rolling out in lofts and suspended floors, for a tight fight between joists. Rigid boards are good for solid walls or across the underside of rafters in an attic room (to add to insulation between rafters). Each of these will come in certain sizes and will need to be cut to shape if you have some unusual spaces. Some materials can be cut with a knife, but a few will need a saw. You should still wear a face mask when cutting and laying any type of installation, because it’s best not to inhale small fibres of any kind.

With any insulation, the right method of installation is needed to avoid problems such as damp, thermal bypass, and thermal bridging (where a solid material spans across the insulation). Materials will often need to be installed with suitable vapour control layers above and/or below them. Suppliers of materials should have guidance documents on suitable layers for different jobs.

Solid walls could be insulated either externally or internally with rigid boards, fixed to the walls with screw fittings, and rendered or plastered. Solutions are available as a package that will include compatible render or plaster, to give a robust finish. If using a fluffy type of insulation, this will need to be held within a timber framework, and careful design is needed to minimise thermal bridging by the timber.

How thick?

The ‘thermal conductivity’ of insulation measures the amount of heat loss, so a lower value means less heat loss for the same thickness of material. It measures heat loss in watts, per metre thickness of material, per degree difference (in kelvin, K) – abbreviated to W/mK.

Most natural fibre insulations will have a thermal conductivity of between 0.035 and 0.040 W/mK, which is similar to polystyrene and glass fibre insulation. Some types of plastic foam have a lower thermal conductivity of about 0.02 to 0.025 W/mK, which means they can be half to two-thirds as thick for the same heat loss reduction. However, they can have issues with breathability in an old house, will have involved more pollution and energy use in manufacture, and will be harder to eventually dispose of.

There are other synthetic materials with even lower thermal conductivity, such as aerogel insulation (like ‘spacetherm’) at only about 0.015 W/mK thermal conductivity or sealed vacuum panels at 0.007 W/mK – but these have much higher costs and embodied energy.

Meeting the standard for solid walls

For a house with solid walls, adding just a few centimetres of insulation has a big effect. Where space is really limited, about 5 centimetres of something like wood fibre insulation board could cut heat loss through the walls by about 75%. Adding about 10cm could result in about 85% less heat being lost through the wall.

Products that are only a few millimetres thick won’t have anywhere near as much effect as adding a few centimetres of insulation, but can cost as much or more. If you have questions about solutions you’ve been quoted for, you can contact us. The U-value that needs to be met for building regulations can be adjusted depending on circumstances. This value measures heat loss in watts, per square metre (e.g. of wall), per degree difference – abbreviated to W/m²K.

There’s a target U-value of 0.3 W/m²K for solid walls, but you don’t necessarily need to meet that. You need to meet the lowest value that is “technically and functionally feasible” and will “achieve a simple payback of 15 years or less” – and that could be up to 0.7 W/m²K (the higher the U-value, the more heat loss). About 5cm of almost any insulation can get you below that 0.7 W/m²K U-value.

Other things will affect the overall heat loss from a house, including the roof and floor insulation, window size and quality, and air leakage through draughts. Some amount of solid wall insulation will be part of reaching a good overall standard.

For more specific guidance on insulating different parts of a house, see the information pages on CAT’s website or contact the information service.

Finding eco-builders and further advice

The AECB promotes sustainable building and retrofit, and you can find eco-builders using their directory of members (enter a location filter to show local contacts). Another listing site for green builders is the Green Register. For links to other places to find local builders, and for more about specialists in particular building materials and techniques, you can contact CAT’s Information Service.

Support our work

Did you know that CAT is an educational charity? If you have found our Free Information Service useful, please consider becoming a member or making a donation to support our work.

The post Understanding insulation appeared first on Centre for Alternative Technology.

During this course, we will examine the operating principles of heat pumps, how they work and what conditions they perform best in. We’ll explore the differences between air, ground and water source heat pumps and weigh up the energy efficiency of each.

Through a mix of lectures and hands-on sessions, you’ll learn about the need for detailed design, both of the system and the recipient building. The course will also cover developing a cost-benefit analysis and quantifying emissions reductions, enabling you to decide whether heat pumps are suitable for your home, community space or business.

Key information:

• Duration: one day
• Upcoming date: Saturday 13th May 2023
• Start and finish times: starts at 10am and ends at 4.30pm
• Fee: £80
• Includes: tuition, all materials
• What to bring: waterproof clothing is recommended

Installing a heat pump requires an understanding of how they work and how to choose the right system for a space.

Your tutor, Dr Alan Owen, will give you all the information you need to get to grips with heat pumps. Alan is a Chartered Energy Engineer and lecturer on our postgraduate courses. His research ranges from numerical modelling of sustainable energy systems and resources in Europe, to developing international sustainable energy policy and strategy in post-conflict/post-disaster areas of Southeast Asia.

A basic knowledge of MS Excel (or equivalent) is desirable for this course.

For more information on this and other CAT courses, please visit www.cat.org.uk/short-courses or contact us at courses@cat.org.uk

Our thanks to Oceanair for installing the air source heat pump used in our renewable energy training courses.

What are heat pumps?

Heat pumps extract energy from the outside air or from under the ground and use this to heat buildings. You’ll almost certainly have a heat pump in your home already, because small heat pumps power fridges and freezers. The process is complex, but basically the heat pump is absorbing heat from one place and moving it to another place. Most air conditioning units are heat pumps, as are efficient types of tumble-dryer.

Heat pumps are often advertised as ‘free heat’, as for a small amount of energy in (electricity) they can emit more energy out (as heat). A small amount of electricity is needed to run a compressor and harness the energy available, and this can be from renewable sources.

Renewables for Households courses

This course is part of a series exploring renewable energy technologies for households. Each course can be taken as a standalone or as a series where they will equip you with the skills and knowledge to implement different renewable technologies in your home.

• Renewables for Households: Wind Turbines – Saturday 22nd April 2023 (sold out)
• Renewables for Households: Heat Pumps – Saturday 13th May 2023(sold out)
• Renewables for Households: Solar PV – Saturday 27th May 2023 (sold out)
• Renewables for Households: Solar Hot Water – Saturday 17th June 2023

Topics already covered this year include an introductory course, biomass and insulation.

If you’d like to explore renewable energy in more depth, take a look at our MSc Sustainability in Energy Provision and Demand Management course, which explores this on a local, national and international scale.

The post Short course spotlight – Renewables for Households: Heat Pumps appeared first on Centre for Alternative Technology.

The course explores how to recognise the warning signs of damp problems, including where past conservation efforts may have gone wrong, and introduces different techniques and methods for reducing or eliminating the problem.

Key topics include:

• How and why damp occurs in the home, and different types of damp;
• Understanding issues around ventilation, wall breathability and the materials used in construction and renovation;
• Annual maintenance and repair issues associated with damp;
• The dos and don’ts of restoring a home;
• The properties and uses of lime and lime products;
• Building surgery – bring any damp issues, details of restoration projects and conservation plans for discussion and advice.

Suitable for beginners, DIY enthusiasts or professional builders without much experience with older housing, the course takes place over two days at CAT.

Nathan has over 30 years’ experience in the construction industry in a variety of roles that have included: carpentry and joinery, historic building surveying, project management, conservation and the restoration of buildings. An experienced tutor, he has taught courses on traditional building methods, traditional carpentry skills, lime work and how to approach costing a heritage project.

Next dates: Tuesday 2  to Wednesday 3 May 2023.

Fees: £320, including tuition, all materials and full board shared accommodation (single accommodation is available for an additional £20).

To find out more visit our Fixing Your Damp House course page or get in touch.

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Heat pumps are a sustainable heating solution that offers longterm carbon and energy savings, with emissions about 80% lower than from a gas boiler. With many of us living in houses that were built long before awareness of the climate emergency and energy efficiency, retrofitting buildings with the latest heat pump technology needs investment and some planning.

Government support in the UK and across Europe for developing the heat pump industry should eventually lead to reduced costs, as happened with solar photovoltaic (PV) technology. But for now, moving to heat pumps and high levels of insulation does require investment.

So, if you’re a homeowner, what funding is available to you and what should you consider before joining the heat pump revolution?

Catch the BUS

The new Boiler Upgrade Scheme (BUS) has replaced the Renewable Heat Incentive (RHI) and is due to run for the next three years (the name is a change from the proposed Clean Heat Grant). It covers England and Wales – with Home Energy Scotland offering different funding.

Now, homeowners should need to do very little, because the installer claims the grant and subtracts it from their quote. You still need to choose from installers accredited under the Microgeneration Certification Scheme (MCS), and it’s worth getting a few quotes to compare. Ofgem runs the scheme and will contact you to confirm that you agree to any work going ahead.

Biomass heating is only funded in rural areas without mains gas. For this, rural means anywhere other than settlements of more than 10,000 people (defined by an Office for National Statistics tool).

As a fixed amount, the grant covers more of the cost of a smaller heat pump, whereas for a larger heat demand it’s probably going to give much less than the RHI did. The new grant is less attractive for ground source heat pumps, as the RHI offered a much more generous rate. And solar water heating is no longer funded.

Share the warmth

For some dense housing, finding space for an air collector might be tricky. Instead, shared heating may work well for small terraces or blocks of flats; for example, one borehole shared by several homes, each with their own internal heat pump unit to upgrade the heat. The BUS covers shared ground loops, but only up to total of 45kW – perhaps five to 10 homes.

Developers of larger heat networks (for hundreds of homes) can apply to the ‘Green Heat Network Fund’ for financial support. One new heat network is using old coal mines near Gateshead as the source (about 15°C) for a large heat pump, with the potential to heat thousands of homes.

Insulate for the future

You don’t necessarily need high levels of insulation for a heat pump to work well. However, insulation and other measures to reduce energy demand enable us to reach a zero carbon grid much more easily and quickly. To cut carbon and running costs we need to do more than just replace boilers with heat pumps on a like-for-like basis.

At present, a well-designed heat pump can have running costs similar to a gas boiler for the same heat demand. The balance would tip in favour of heat pumps if changes were made to the way levies are applied to energy bills. These levies fund useful programmes but are almost all added to electricity bills rather than gas – making the comparative running costs of a heat pump slightly worse than it should be. But ultimately, the main way to reduce bills is to cut heating demand.

Save your energy

Unlike the heat pump grant, support for insulation and other energy saving measures is mostly means tested.

In England, there’s support for households with a gross annual income less than about £30,000 who own or privately rent a house with an EPC rating of D or worse. This ‘Sustainable Warmth’ programme combines the ‘Local Authority Delivery Phase 3’ for homes with mains gas and the ‘Home Upgrade Grant Phase 1’ for those without. Your local authority will have details of how to apply for this funding in your area.

In Wales, the Nyth/Nest scheme gives grants to households on low incomes. Home Energy Scotland offer zero-interest loans with additional cashback offers across a range of energy saving and renewable energy measures.

Cut the VAT

A zero VAT rate on both installation and materials is now applicable across energy saving measures and renewable energy (such as heat pumps, solar, wind and hydro power). Also, the ‘60% test’ has been dropped – this previously prevented applying a low rate of VAT on materials (such as solar panels) if they came to more than 60% of the total installation cost.

However, as with previous low VAT rates, this is for professional work not DIY insulation. There’s also a separate new issue for planned micro hydro projects, as it looks like much higher abstraction fees could make small schemes less financially attractive (outweighing VAT savings).

Planning on installing a heat pump?

Here are some recommendations and important things to consider.

• The installer must do a room-by-room heat loss assessment to ensure the heat pump is not over or under sized. A properly sized unit will run more efficiently.
• ‘Monobloc’ air source heat pumps make installation easier because these have all the workings in the outdoor unit, so you don’t need a separate indoor unit.
• To reduce running costs, most of the time you can heat your domestic water cylinder to a lower temperature that meets household needs – and only cycle it
  up to about 60°C once or twice a week to meet legionella regulations.
• To get a very high efficiency, aim to get a system designed and sized so it can heat your home on flow temperatures of 40 to 45°C when it’s -3°C outside.
• To improve efficiency, use emitters that have a decent amount of mass, such as radiators with a high water volume or underfloor heating pipes in a thick screed. This can then avoid the need for a buffer tank and make it easier to keep flow temperatures lower.
• Microbore (very narrow) pipe is not a barrier with good design (a buffer tank may be needed).
• Modern air source heat pumps are very quiet, and with sensible siting (not under your bedroom window) the noise should not be an issue. They do vibrate slightly, but ground mounting will avoid any risk of vibrations from wall brackets.
• A hybrid of heat pump and boiler could give more flexibility for a large house, but it does mean more servicing fees and more standing charges, as well as higher carbon emissions. Moving away from gas completely (including for cooking) could save about £100 per year on standing charges. There’s a charge for disconnecting, but some electricity providers may not pass this on to customers.
• For space heating, a heat pump is often set to be operational all the time, but this doesn’t mean it’s actually running all the time – just that it’s ‘on call’. And you can set lower temperatures for different times, such as overnight.

About the author

Joel Rawson is CAT’s Information Officer, providing free and impartial advice on a wide range of topics related to sustainability. He first came to CAT to volunteer in 2001, and graduated with a CAT Postgraduate Diploma in 2013.

CAT’s free information service

Still have questions? Visit cat.org.uk/info for information and advice on a wide range of areas related to homes, buildings, energy and more.

The post Get warmed up to install a heat pump appeared first on Centre for Alternative Technology.

Bio-based materials and construction company IndiNature, co-founded by CAT graduate Scott Simpson, have received backing from the Scottish National Investment Bank to open a dedicated natural insulation factory in the Scottish Borders.

Once local recruitment is complete, the factory will start manufacturing IndiNature’s flexible hemp insulation batt ‘IndiTherm’ at high capacity, ready for launch in summer 2022.

IndiNature’s vision is to transform the construction industry and existing damp and cold housing stock by providing a widely available safer, carbon negative solution to insulation for use in UK households and further afield.

As well as manufacturing a carbon negative product, IndiNature plan for the factory itself to be a showcase of sustainable systems, which Scott says CAT was useful in informing. They will use renewable technologies to power the factory and good design principles throughout.

IndiNature estimate that at full capacity, the factory will capture 10,500 tonnes of CO2 a year, which by 2050 will have the equivalent impact as planting 5 million trees.

During his time at CAT, on one of our Graduate School of the Environment postgraduate courses, Scott was able to experiment with industrial hempcrete in the lab, gaining technical skills he says helped in choosing appropriate materials. IndiTherm is made from UK grown industrial hemp which captures carbon as it grows and results in a product that is reusable, recyclable and biodegradable.

As well as the backing from Scottish National Investment Bank, IndiNature also received grant funding of £803k from Zero Waste Scotland and £250k from South of Scotland Enterprise.

On the IndiNature website, Scott Simpson CEO said

“We couldn’t be happier having the Scottish National Investment Bank back us. It feels great that we can move forward to create local Borders jobs and make insulation on scale in Scotland – insulation that’s good for people’s health and the planet. 

The demand for local, natural alternatives in construction is increasing. At IndiNature we love using crops from UK farmers – it’s so critical the world moves faster toward what’s known as the circular bio-economy by using plants in products, to reduce waste and naturally capture carbon. 

Our news coincides with the latest IPCC (Intergovernmental Panel on Climate Change) report this week which calls for urgent action. Amongst the fires and floods we’re seeing globally, IndiNature aims to be a Scottish showcase of positive action.” 

We recently spoke to Scott about IndiNature’s story in the last issue of Clean Slate. You can read the blog here.

Congratulations to IndiNature – we’re looking forward to seeing this zero carbon solution scale up over the next few years.

Inspired to study at CAT?

If you’re inspired by Scott’s story and would like to find out more about studying on a CAT postgraduate course then get in touch with Alis Rees, Graduate School Marketing Officer. Or if you’d like to read more CAT Stories about the inspiring work and solutions other graduates are working on then you can read their profiles here.

The post IndiNature receive £3m investment to open UK factory appeared first on Centre for Alternative Technology.

Reducing heating demand is key to a zero carbon future, because it’s then far easier to install enough renewable energy to meet the remaining demand. Upgrading insulation makes the biggest impact, but air infiltration also causes significant heat loss.

In CAT’s ‘Zero Carbon Britain: Rising to the Climate Emergency’ report we recommend building new homes to the ‘Passivhaus’ standard or similar. That means stringent airtightness and mechanical ventilation with heat recovery (MVHR).

We also recommend a mass refurbishment of existing buildings. A whole house retrofit may well also lead to using MVHR to give good indoor air quality, but in some cases passive (nonpowered) ventilation, or a mixture, may be enough.

Unintentional vs intentional ventilation

‘Build tight, ventilate right’ is a longstanding energy efficiency mantra. The aim is to stop unintentional ventilation and instead provide intentional ventilation. Airtightness applies to the entire building fabric: gaps and cracks at the corners and edges where materials join, holes for pipes and cables, where joists penetrate a wall, and so on.

The benefits go beyond energy savings. The right approach to airtightness actually makes a house feel both fresher and more comfortable. The thermostat tends to be cranked up in a draughty house to counteract the cooling effect of incoming air flows. In contrast, with low air movement a home remains comfortable at a lower temperature.

With good airtightness, effective ventilation replaces stale air – including carbon dioxide, cooking smells, water vapour, dust, off-gassing (for example from new appliances), and so on. If a building isn’t airtight enough, planned airflows for some types of ventilation won’t work as intended.

In addition to draughts, ‘thermal bypass’ can cause further heat loss. This is when outside air gets past the insulation layer and into spaces within the building fabric. The ‘dot-and-dab’ technique for quickly fitting plasterboard creates voids prone to thermal bypass. It also happens when spaces in a roof or intermediate floor aren’t properly sealed when being insulated. As well as heat loss, these cold patches are at risk from mould growth.

Measuring airtightness

The first step is to know your starting point by having an airtightness test. Then you can set a target for improvement and a strategy to achieve it.

Airtightness in older buildings varies a lot, and you can’t tell just by looking. Using thermal imaging during a test helps to identify heat loss from air leakage, by comparing cold spots visible during the test to those when unpressurised. A local energy agency or community organisation may be able to provide an initial survey.

A blower door test shouldn’t be very disruptive or expensive. Existing ventilation points like extractor fans, trickle vents, and flues are sealed. A powerful fan extracts air to create a pressure difference that amplifies air infiltration, allowing you to measure nonintentional ventilation. You may want the
test to give two measures:

• Air permeability relates to the surface area of a building. It’s used in UK building regulations. The units are cubic metres of air per hour per square metre of surface area: m3/h.m2@50Pa (tested at 50 Pascals pressure).
• Air changes per hour (ach) relates to the volume of a building. It’s used in high standards such as Passivhaus (1ach@50Pa for retrofit) and AECB retrofit (2ach@50Pa).

These could be very different, especially for a less compact layout with a high surface area. When speaking to contractors make sure you’re both talking about the same measure.

Aim and strategy

Once you have a baseline, you can decide on an airtightness target that is practical for your project, considering also the type of ventilation you’ll then need.

A typical modern house probably has an air permeability of about 5m3/h. m2@50Pa. Some older homes are similar, but many are much leakier.

Recommendations vary, but for mechanical ventilation to be appropriate you’ll probably want less than half that. However, MVHR proponents say that the dedicated air intake means it saves energy even if airtightness is only to a reasonable level.

To deliver a more exacting target you need an airtightness strategy. This specifies where the airtight layer will be, with details for all the junctions, gaps and holes. When going for a tested standard, set your target to give a bit of margin for error.

Hitting the target

Make sure that the target and strategy are clear to your architect and builders, because effective ventilation depends on it. Because attention to detail is vital, you need a good relationship with contractors and they must be fully engaged with the process. Stringent airtightness is still new to many in the UK, and having a ‘no blame’ culture allows you to get mistakes fixed before it’s too late.

There are special tapes and grommets for sealing junctions and problem areas, such as where electricians and plumbers run pipes and cables out of the building or into an uninsulated loft. Other weak points include recessed lights and the loft hatch. For some older houses secondary glazing might be a less costly option than replacement glazing for getting the required airtightness at window frames.

Ventilation types

Mechanical ventilation with heat recovery (MVHR) extracts warm stale or moist air, generally from the bathroom and kitchen. A heat exchanger transfers the heat to incoming fresh air for other rooms. The filtering of incoming air is an advantage where outdoor pollutants are a concern. MVHR should have very low running costs, saving much more energy than it consumes. However, as a decent Passivhaus-certified system will cost a few thousand pounds, the retrofit must be to a suitable standard to make it worthwhile.

Ventilation that only extracts air needs very good airtightness and careful design to draw enough fresh air in to where it’s needed (through trickle vents or similar). In a well-draught-proofed house, passive ventilation depends for success on manually adjusting windows or other inlets as required. You can supplement a mostly unpowered approach with a small heat recovery fan for the bathroom (perhaps also the kitchen).

Pitfalls

Passive or mechanical ventilation can fail to deliver if there are mistakes in the design or installation or if it’s not maintained – resulting in a stuffy, humid and unhealthy house. A successful approach must work under normal living conditions, for example don’t rely on leaving bedroom doors open.

Poor design or installation of a mechanical system could make it noisy. Large diameter ducts and a low air resistance heat exchanger keep the noise and energy use of fans very low. Rigid ducting is preferable to flexible, which may be easier to install but tends not to perform well. In general, flexible ducts lead to more noise, are harder to clean, and don’t last as long. For heat recovery to work efficiently, the MVHR unit and ducting should be within the insulation layer, not in an uninsulated loft where they’ll lose heat.

Check the maintenance required to keep a ventilation system efficient and healthy, and that there’s access for this. For example, with an MVHR system you’ll need to check the filters every few months and clean or replace as necessary. Replacement paper filters might cost £10 to £15. You may need a more thorough servicing and cleaning of the heat exchanger and fans every few years.

Finding help

Getting good advice upfront should give big savings later. Local community based organisations are ideal as trusted intermediaries – bringing together householders and local tradespeople, and supporting both. At the moment, there are organisations like this dotted around the UK, with more gradually springing up. There are also bodies like the AECB (Association for Environment Conscious Building) and Passivhaus Trust that list professionals trained to high standards.

About the author

Joel Rawson is CAT’s Information Officer, providing free and impartial advice on a wide range of topics related to sustainability. He first came to CAT to volunteer in 2001, and graduated with a CAT Postgraduate Diploma in 2013.

The post Build Tight, Ventilate Right appeared first on Centre for Alternative Technology.

Solastalgia: “The distress induced by environmental change and the degradation of one’s home place.” Currently under review for inclusion in multiple dictionaries.

Our homes are often the place we find shelter, comfort and security, both physically and mentally in our lives, that space to call our own, to inhabit as we wish.

Meanwhile our skies and lands are emptying, the cacophony of noise from our natural environment quietens. A collective sense of distress continues to dawn on us: the solastalgia begins to ache our souls.

In the world of design and construction we continue to build, clearing and levelling landscapes, laying foundations, erecting structures, and sealing them up for energy performance. It feels like an inherently damaging activity to be a part of, and yet we do need to continue building. We need to be more selective about how and when we choose to build but the need to maintain, renovate, retrofit and, when appropriate, build to enhance our collective wellbeing and standard of living, rebalancing the injustices of how and where we dwell is undeniable.

So how can we build in a nature friendly way? How, as a homeowner or tenant, can you mitigate your impact on nature? The good news is that there is a huge amount we can do as individuals, in every part of our lives. As architects, designers and housebuilders there is even more we can think about.

Make space for wildlife

Whilst it’s vital that we look at the wider picture, including protecting areas of wilderness, improving agriculture and land management, tackling climate change, and taking part in collective actions to push for change at a policy level, what we do in our own homes and gardens can also have an impact.

If you are lucky enough to have a house where swifts, house martins or bats (to name but a few of the many species that might use our homes as their homes) already choose to roost or nest, then make sure you take good care of them by leaving them be. If they are a nuisance, producing a mess, take pride in clearing up after them or install a shelf to catch any droppings. Tell your neighbours, and sit out together to marvel at the wonders of the wildlife on your doorstep.

For those that do not have any wildlife nesting in their home but are fortunate enough to have a garden, this is where you can have great impact in encouraging biodiversity. Look at the borders of your garden. Think like the wildlife that you want to see in your garden. If you were a hedgehog, a fox or a great tit, would you be able to get into the garden? Would it be enticing? Are there places to take cover from humans or their pesky pets? Install hedgehog highways, replace fences with hedges and get rid of that plastic grass!

Next, look at what’s within your garden, follow some basic principles to encourage wildlife; celebrate variety and diversity of planting, expand the edge space where habitats come together, and avoid tidying up where possible. You can apply this thinking right down to window planters or pots on a balcony to encourage the birds and bees right to your window.

You can go one step further and give nature a home by installing nesting or roosting habitat for some of our native species. Speak to local wildlife enthusiasts and ecologists to see what species are present nearby and if installing a nesting or roosting habitat would be appropriate for your home.

We also need to be aware when inviting wildlife into our gardens and near to our buildings that human structures can present a hostile environment. Our windows become mirrors, and can look like holes through which to fly or identical rivals to ward off; unwoven building membranes can entangle the tiny claws of bats, and drains are the unfortunate pitfall for our amphibious friends. Minimising the dangers to wildlife from our buildings and their infrastructure is key; we can do this by installing drain guards, mesh and other tools. If your windows are prone to bird strikes you can make and install your own window manifestations (stickers on your windows) or add blinds internally.

Enjoy dark skies

One of the biggest impacts from our homes and built environment is our excessive and inefficient use of lighting, affecting the natural rhythms of a range of animals, including ourselves.

Install hoods over all external lighting, directing it only where it is absolutely needed. If you are replacing outside lights look out for fixtures that are directional and low level.

For internal lighting, something as simple as closing the curtains or turning off the lights in the rooms you are not using will help any wildlife present outside, save your energy and give you a much better view of the beautiful night sky!

An architect’s perspective

There is a great deal the architectural profession needs to do to improve how it works with and encourages nature friendly building. There is a need to understand the holistic issues of material specification and choice, master planning, landscaping and detail design, and how at every level these decisions have an impact on wildlife.

Materials are specified for a range of reasons, including aesthetics, and thankfully embodied carbon (the carbon emissions from the manufacturing process) is now becoming a material consideration that is widely accepted within the industry. But we need to understand the further hidden impacts from harvest or extraction, processing and manufacture, and examine whether these are causing ecological harm through unsustainable management or release of pollutants. Only when looking holistically at material choice can we make informed ecological decisions.

The simplest way to reduce our impact on material and resource use is to prioritise retrofit over new build. Improving energy efficiency through retrofit or building to a very high level of thermal performance will have a knock-on benefit to wildlife by ensuring we minimise the impact of our homes on global heating and climate breakdown. Another issue related to careful use of materials is when wildlife chooses to nest within, and not upon, buildings. This is of particular concern with ‘natural building’ techniques as the materials are inherently familiar and hospitable for wildlife to nestle into. This can cause serious harm to the fabric of a building, reducing thermal performance and longevity, both of which are hugely important when considering energy conservation and the embodied carbon of construction. You can avoid your home becoming a mouse nest or bug hotel by making sure you hire a builder that is experienced in using natural materials, and look to provide opportunities for more suitable habitat creation through careful design and detailing.

Conversations and collaborations

Compounding the issues for architects attempting to navigate projects through the unpredictable natural environment is that during their seven years of training they will rarely, if ever, have a conversation with or hear from an ecologist.

This is something we actively try to address in teaching our Masters in Architecture at CAT. As with all of our ‘technical education’, we do not seek to make our students expert in other fields but to raise their understanding and awareness to a position whereby they can have an informed conversation with a professional. It is these informed conversations between ecologists and architects which provide opportunities to proactively make our built environment more nature friendly.

A helping hand

There is a huge amount that can be done to improve our built environment and homes to make them more nature friendly, as part of wider efforts to combat the climate and biodiversity emergency. Nature needs any helping hand we can give it so we must embrace every aspect of both reducing the impact of construction on the natural environment and in creating space for nature in our homes and gardens.

When thinking about buildings, the built environment and the impact of our lives on the wildlife we share the planet with, we need to think from an ecocentric point of view, considering the needs of every species, and not just those of our own.

About the author

Gwyn Stacey is a Senior Lecturer on CAT’s MArch Sustainable Architecture course. He is a former student of CAT’s Professional Diploma in Architecture and now, alongside his role at CAT, is developing his practice work with a community focus in rural Wales, and working with and supporting conservation organisations.

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During the winter months, gardens and backyards can be a vital lifeline for many of our native species. With plummeting temperatures, reduced food supplies and adverse weather to battle with, it can be a struggle to survive the season.

However, some easy adjustments to our outdoor spaces may make all the difference to the wildlife on our doorstep. And that doesn’t have to mean pricey garden centre buys or hours of work.

Below are some quick and simple tasks for ensuring wildlife can thrive in your garden all winter long.

Break the ice

A prolonged freeze can result in numerous problems for wildlife.

Frozen bird baths restrict the birds’ ability to keep their feathers in tip top condition and limit access to fresh drinking water.

Cold weather can significantly impact amphibians if a layer of ice forms over the surface of the spawn. Frogs may lie dormant at the bottom of the pond and, while only a small percentage of the local population may be affected, some may succumb to ‘winterkill’ (oxygen levels within ponds can fall and toxic chemicals build-up). While it is a natural cause of mortality, maintaining a hole in the ice can be used as a precautionary measure.

The easiest solution to prevent freezing is to place a ball or another floating object in the water. Never pour hot water on to the ice or use chemicals or salt. It’s also not advised to crack the ice manually as this can cause distress to hibernating animals, and can potentially damage pond liners and plants.

It’s a good idea to create a nearby rock pile habitat, where amphibians can take shelter. Ideally, this should face north, to avoid temperature highs and lows between day and night. These areas are popular with cold-blooded animals such as frogs because the stones “hold” heat and cold longer than the air around it. The area near a rock pile also tends to stay moist, which some creatures prefer.

Feed the birds

Feeding birds throughout the winter is important because it greatly increases their breeding success the following year. With just a couple of bird feeders, you can provide birds with essential nourishment until spring.

Different birds are attracted to different foods, so providing a diverse selection of foods is a sure way to cater for every feathered friend. For instance, finches prefer smaller seeds like nyjer, whereas tits opt for the high energy content of sunflower seeds.

If you’re using feeders, it’s crucial to sterilise them regularly to reduce the risk of spreading diseases – keep a close eye out for lethargic birds sitting around with their feathers fluffed up.

More secretive and ground-feeding birds, such as dunnocks and wrens, would appreciate a sprinkling of crumbled fat balls and seed beneath shrubs. You can even smear fat mixtures into the cracks and crevices of bark for treecreepers, nuthatches and woodpeckers.

Grow your own bird feed

Ultimately, the most valuable way to feed birds in winter is to simply let nature provide. Planting shrubs, trees and hedges can offer a variety of flowers, catkins, leaves and berries which attract and feed a whole host of animals, particularly birds. Furthermore, this added vegetation gives cover from the elements and valuable protection from predators.

If you don’t have a lot of available space, growing in a container could be the solution. Smaller species such as crab apple are a real wildlife winner with its bright coloured fruits providing food for a diversity of species. Its flowers are also an important source of early pollen and nectar for insects.

The joy of being messy

If you can leave an area of your outdoor space naturally unkempt, you can help support a range of species over the winter period. Even the smallest of gardens can offer up a huge variety of different habitats for wildlife. Embracing nature means less work, more wildlife and a more ecologically interesting garden.

One of the easiest things you can do is simply leave twigs, fallen leaves and dead vegetation as these provide nesting materials as well as important shelter. You can further enrich habitat by creating a log pile in a shady spot and leaving it to decay. As well as supporting a large range of fungi, your little creation could offer refuge for hibernating hedgehogs and toads.

Life on the compost heap

Compost heaps can be miniature nature reserves in themselves – they are incredible places for insects, worms and invertebrates to thrive. Creatures such as birds, bats, hedgehogs and small mammals are attracted to this satisfying feast, acting as natural pest controllers. The addition of a compost heap not only provides a feeding area for a wide range of species, it also enriches and improves soil structure.

Another tip is to give your mower a break this winter – the less pristine the lawn, the more beneficial it is for wildlife. Weeds can help boost biodiversity in your garden; for example, clover is of great value as it feeds nitrogen to your lawn. Dandelions, often not tolerated in gardens, are tremendously prized by several different pollinators. Creating a patch of longer grass encourages more plant diversity, whilst also offering habitat for the insects on which birds and other wildlife feed.

Helping hogs

The statistics feel stacked against our beloved hedgehog.

Sadly, nearly half of all hedgehogs do not see past their first winter. Hogs born in late-summer struggle as their fat reserves are simply not enough to see them through hibernation. In addition, with climate change making our winters milder and milder, hedgehogs can awaken too early and waste valuable energy searching for food.

As mentioned earlier, hedgehogs can be thrown a lifeline if we make log piles, and long grass encourages the hedgehog’s prey. But what else can we do to help these endearing creatures survive winter?

Always check bonfires before lighting them, you never know what could have decided to shelter in there. It’s best practice to only build one on the day you intend to burn – this reduces the chance of a hedgehog or other animal becoming attracted into it.

Instead, hedgehogs may be enticed into a cosy hedgehog house to hunker down in the harsh winter months. These are fairly simple to make, otherwise they’re readily available from wildlife specialists or pet stores.

Should a hedgehog wake up early from their slumber, access to food is an absolute necessity. Setting up a feeding station offering hedgehog food or meaty pet food and water would help preserve the energy of a desperate hog caught out by our unpredictable climate.

Read more about what we can do to help hedgehogs.

Help nature thrive

As more and more of our native wildlife is lost to the interrelated threats of climate change, pollution and habitat loss, we need large scale changes in energy, industry, buildings and land use to address the climate and biodiversity crisis and create more space for wild nature to flourish.

Collectively, what we do in our own gardens and window boxes can also make a big difference, providing much needed food and shelter for a wide variety of species.

And one last tip – spread the word. Whilst individual gardens can be little wildlife havens, by working together we can create corridors where creatures such as hedgehogs are safe from traffic and can roam freely in search of food.

Talk to your neighbours and encourage them to join you in providing food, shelter and space to help wildlife survive and thrive through the toughest of seasons.

About the author

Dulcie joined the CAT woodland team as Natural Resource and Volunteer Officer in August 2020. She has spent the first few months of her role setting up camera traps and footprint tunnels in preparation for CAT’s hosting of BBC Autumnwatch.

She has a BA (Hons) in Marine and Natural History Photography, a course that devoted heavy emphasis on environmental subjects and concerns.

Did you know that CAT is an educational charity?

Please consider supporting out work by becoming a member today.

The post A helping hand for winter wildlife appeared first on Centre for Alternative Technology.

As the temperatures drop and natural supplies become scarcer, life can be particularly tough for garden birds and other wildlife at this time of year.

Shorter winter days leave birds less time to find food just when they need enough energy to keep warm. And, with our native wildlife under more pressure than ever before, any small helping hand you can give – whether you have a big garden or a small window box – will help them get through the extremes of the winter months.

Here are some tips on what can be put out for wildlife to enjoy, and what foods to avoid.

Tasty titbits to share

If you’d like to encourage badgers, they have an appetite for unsalted peanuts, brazil nuts, root vegetables and bread (which can be soaked in water or spread with peanut butter). Foxes would be grateful for any scraps – they are by no means fussy creatures – but if you have leftover meats (cooked or raw), these would certainly go down a treat. Only leave enough that can be eaten in one day to avoid attracting unwanted visitors, such as mice and rats.

Dried fruit, unsalted nuts, or sliced apples and pears past their best will greatly benefit any garden visitors. Boasting a high water content and plenty of natural sugars, fruit is ideal for providing garden birds with the added energy they need to survive winter.

Mild grated cheese is a firm favourite with robins, dunnocks, blackbirds and song thrushes. You could even try sprinkling some under trees and bushes for more timid birds such as wrens and dunnocks. It is best to avoid strong or blue cheeses, stick to stale, hard cheeses like mild cheddar.

Another big hit is potatoes – you can roast or mash them (with added real fats) to be a festive delicacy for your feathered friends. If you are offering baked potatoes, they need to be cold and opened up.

In the unlikely event there is a spare mince pie or some stale cake left over, you can share them with your birds. Break up any large pieces, and if it’s very hard you can soak in a little water to ensure birds don’t choke. However, it’s worth noting that some pets react badly to dried fruits such as grapes, currants, raisins or sultanas – this is something I must always consider, as my dog is practically a hoover and would not hesitate to eat what he shouldn’t.

Fresh water sources

If you’re putting out lots of tasty food, it’s also worth providing fresh water to help wash it down. This can be difficult for birds to find during cold periods as natural sources start to freeze over. Water to bathe in is essential so that they keep their feathers in good condition, and they will need to do this even in the depths of winter.

You don’t have to have a pond or birdbath, even an upturned bin lid or a simple plant saucer can give birds the liquid they need. Putting a light ball (such as a ping pong ball) or even a cork in the water will help keep it ice-free for birds to use.

A tale of caution

As exciting as it is to encourage wildlife in your backyard, it is vital to be aware that it is possible through kindness to cause harm.

Not every leftover is suitable for sharing with birds and wildlife. Below are a few snacks that should not be offered to our feathered friends.

Most importantly, putting out excess cooking fat is a big fat no-no. Unlike lard and suet, cooked turkey fat remains soft even when cooled, meaning it can get onto birds’ feathers and ruin their waterproofing and insulating qualities. Furthermore, juices mixed in roasting tins will go off very quickly and could cause disease on bird tables. Birds are very susceptible to disease at this time of year as their defences and energy levels are lowered due to the cold.

Instead, why not create your own calorific delicacies for the birds by making your own pinecone feeder. This can be a fun family activity to enjoy together – and it helps keep your birds fed this winter.

In light of the current spread of avian flu, the RSPB advises that we maintain good hygiene at bird feeding stations. While it is extremely unlikely that bird flu could be transmitted to people by feeding birds in the garden, it’s a sensible measure to follow hygiene guidelines. Bird feeders should be washed and cleaned regularly to prevent spread of diseases such as salmonella.

Another key thing to note is that too much salt is toxic to garden birds as they are unable to metabolise it. It also makes them excessively thirsty and at risk of dehydration, so never put salted food on the bird table. A good rule of thumb is that foods that are generally unhealthy to humans are likely to be unhealthy to wild birds too. While this isn’t always the case, it’s a handy reminder that putting out processed fatty foods is best avoided.

And finally, once you’ve established a feeding routine, do try to stick to it as birds will keep coming back for more once they realise there’s a new food source in town, and they’ll adjust their routines to suit.

Help nature thrive

In an ideal world, birds and other wildlife would not be dependent on scraps from our table. Ultimately, we need to change how we use land so we can create much more space for nature to thrive; this will mean doubling forest cover, restoring lost habitats and supporting more farmers to produce foods in wildlife friendly ways.

In the meantime, you can help your garden wildlife to survive the coldest season by responsibly supplementing their diet. By using food that would otherwise be discarded, households can take a small step to becoming more sustainable and eco-conscious for future generations.

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The development project will be co-funded by Innovate UK, the UK’s innovation agency to develop new techniques to take CO2 from emitting processes, such as lime and cement and locking this into construction products, like the companies award-winning Breathaboard technology.

The project also builds on the strong relationships that Adaptavate has built with the University of Bath and Biocomposite Development Centre in York. In parallel the project is also asking the question; can the waste of these materials be used as soil nutrients for use in agriculture, to grow more crops and bio-materials, completing a circular economy approach to construction bio-materials?

Ground-up construction waste will be compared to the digestate from Anaerobic Digestion (AD) of the same material. The AD process also generates synthetic gas, predominantly Methane. Here a second and third nutrient loop can be exploited as the Methane created can be burnt to create electricity to run the factory, creating CO2 , which can sequestered in the curing of new material. This is totally in line with Adaptavate’s purpose: to positively disrupt the material flows in the construction sector.

CAT graduate and Managing Director of Adaptavate, Tom said:

“This is a really exciting project at a pivotal point for Adaptavate. It enables us to grow the team and technical partnerships at a really exciting time in our industry. It affirms Adaptavate and the partner universities as leading the way in CO2 sequestration in building materials and industrial processes – helping us reach ambitious CO2 targets that are being set by governments and industrial bodies”.

At the end of his MSc Tom focused his dissertation on developing a product that balances performance, workability, and sustainability which in turn led to the founding of Adaptavate where Tom and now other CAT graduates including Jeff Ive, Technical Director at Adaptavate set to rethink and redesign the way building materials are produced, used and disposed of.

Jeff Ive, Technical Director at Adaptavate said:

“Environmentally positive solutions are not one size fits all, and neither are business cases. This project will allow us to scale the next generation of bio-materials though absorbing CO2 from emitting processes all over the world through localised production models. This is a really transformative way of looking at this conservative, vertically integrated industry that is looking for a step change”.

Jeff has also been a guest lecture on our postgraduate courses showcasing Adaptavate’s work and their products, providing our students with invaluable knowledge and insights from within the industry.

We look forward to seeing how the project progresses and if you’re interested in following their work you can find out more on their website.

Interested in becoming a CAT student?

Inspired by Adaptavate’s story? Want to develop the skills and knowledge to make a real difference in your chosen field? Find out more about our postgraduate courses on our next Virtual Open Day  or get in touch with our Graduate School Marketing Officer.

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