Below we discover how the buildings in which we live, work and spend our leisure time could have the minimal possible negative impact on our environment.
The buildings in which we live, work and spend our leisure time must have the minimal possible negative impact on our environment. This will even improve our quality of life – by avoiding toxic synthetic materials, we can be healthier. For example, evidence even suggests that the hearts of children who are educated in nursery schools made of only organic materials beat less rapidly and the children are calmer and happier, and houses can be kept warmer at less cost.
All new-build houses must be energy neutral or better – they generate more energy than they consume through heating. Some people may be familiar with the PassivHaus standard, but this is only one approach and it requires a lot of plastic in construction, so there are better options that can deliver the same performance. Building regulations must be quickly updated to enforce these new standards so there is no negative impact of housing that a future generation will have to clean up.
But good building is about more than thermal performance; construction itself emits a lot of greenhouse gases where it uses materials like concrete, and leaves a toxic legacy if it uses other materials like plastic. Though some of these materials may be unavoidable, their use and their impact must be minimised. The first way to do this is to build to last – many modern buildings are torn down after only a few decades, so none should be built without a guaranteed lifespan of 60 to 100 years (or longer).
The second is to design out non-organic materials. Construction in Scotland should be dominated by wood, a plentiful and renewable material which actually locks in carbon. Almost all our insulation should be fibreboard or cellulose, both wood-based products. Modern wood technologies such as advanced cross- lamination mean wood can be extremely structurally powerful and even replace steel – the world’s tallest wood-and-glass-only building is an 18-storey ‘plyscraper’ in Norway, and this is what we should be building in Scotland. Where non-renewable materials are used they should be recycled – old concrete can be used to produce new concrete with only a fraction of the carbon emissions.
Currently only about 20 per cent of Scotland’s construction materials are sourced in Scotland. Changing how we build would not only improve quality of life and prevent environmental harm but would generate new supply chains which would greatly stimulate the Scottish economy and create many high-quality jobs. But we must also fix the legacy of Scotland’s 2.5 million existing homes. Bringing all of these up to the standards we will expect of new-builds would be difficult and, if we decarbonise our heating systems, would be hard to justify even in environmental terms. But achieving 90 per cent thermal efficiency for most homes is perfectly possible and almost all buildings (other than historic and architecturally sensitive ones) can achieve 70 to 90 per cent efficiency.
This can be achieved with four basic techniques. Most heat is lost through roofs and even if a house has had loft insulation fitted it is probably still leaking heat (often due to poor installation), so better roof insulation is needed. The next biggest source of heat loss is draughts and so draught-proofing comes next. The third priority is windows; any single glazing must be replaced and older or poorly installed windows need to be renovated or reinstalled to end heat loss. The final step to be taken in the vast majority of existing houses is to make sure basic energy-saving techniques have been implemented, such as replacing incandescent lightbulbs.
A public National Housing Company should be set up to complete all of this work. It will cost an average of £15,000 per house to complete and must rapidly recruit about 6,000 staff who will, between them, be able to retrofit about 60,000 homes a year. To complete everything within 25 years this workforce must quickly double. About a third of the staff will be skilled trades so a major training programme will be needed. Almost all the materials used should be wood-based.
Commercial buildings and private landlords must also bring their properties up to 90 per cent thermal efficiency. This cannot be publicly funded, however the National Housing Company can offer a cost-efficient package with the strong incentive of long-term energy cost savings. There is a strong case for small businesses to be given substantial discounts, but since each citizen will have their primary property renovated at public cost, landlords will need to shoulder the cost of the upgrade for their commercial properties. However, these costs can be absorbed over time by savings in heating and electricity bills.
Industrial plants should have heat recovery installed and connected to the district heating system explained below. This leaves mainly public buildings such as schools, hospitals, sports centres and local authority headquarters. There is little information on what upgrading these buildings will cost and so a major audit of public buildings must be undertaken. There is high potential for energy generation here (because of substantial roof space for solar). and so the aim should be to achieve energy neutrality (generating as much as they consume). Decarbonising heating is a really tricky problem and so is considered in the next chapter. This leaves a final aspect of buildings; the electrical appliances we use in them. Scotland should move rapidly to require all electrical goods sold to achieve a AAA energy rating.