
Our Environmental Action

Most of our team are actively involved in outdoor pursuits of one kind or another; fishing, climbing, hill walking, running, surfing, sailing, skiing, and mountain biking. Quite a list! This love of the outdoors engenders an increased sense of environmental awareness, which we try to apply to all we do here at Sanctum.
We believe that our connection with nature drives our commitment to sustainability and eco-friendly practices in every aspect of our work.
Sustainable Practices & Material Choices

All our Garden Rooms are designed with a ‘Fabric First’ approach. This involves maximising the performance of the materials that make up the building so that there is no redundancy (reducing its carbon footprint) and that the building envelope performs efficiently with benefits in ongoing running costs. This means that the materials we choose need to perform at the highest level without having a negative effect on the planet. The practicality of this can be seen in our material choices below.
When we first started out building garden rooms (2008) we used to use a LOT of concrete in our foundations. We didn’t really understand back then how bad concrete is environmentally, one tonne of concrete produces about one tonne of CO2 in its production. So in 2010 we had a new foundation system designed with the help of a structural engineer which eliminates 90% of the concrete we used to use. It’s also much quicker and much less messy than the concrete slab approach, so win-win!

Sustainable Timber
All our buildings are constructed using tried and tested timber frame methodology. Building in timber is an environmental no-brainer. Wood is THE most sustainable construction material in the world—it literally grows on trees! However, we would caveat that by saying that it needs to be responsibly sourced, and we ensure that by using only construction timbers that are certified by the Forestry Stewardship Council (FSC). This means that the timber only comes from managed forests that are re-planted after logging, and also looks at the animal welfare in the forests, as well as the welfare of the people working in them around the world.
Timber & Climate Change Mitigation
It’s important to differentiate deforestation in developing countries with well-managed forestry operations that re-plant more than they fell every year. Timber products contribute to the mitigation of climate change by ‘locking in’ the carbon that the tree absorbed during its growing lifetime. Replanting felled trees also starts the locking in of carbon again, as trees absorb most CO2 when in their young growing life. Well-designed timber buildings are literally carbon stores. By prioritizing responsible timber sourcing, we can ensure that construction remains both sustainable and beneficial for the environment.
The Highest Quality Materials
High-Performance Insulation for Sustainability
The insulation we choose to use is the best insulator for a given thickness available today. It is also the most expensive, but we consider it THE most important part of your garden room from a sustainability perspective. PIR insulation provides 2.5–3 times more insulation for the same thickness as a fibreglass type of insulation. The companies we use to supply this have the highest environmental certifications available, such as EPD’s, which were brought in to eliminate spurious and misleading claims about environmental performance.
Eco-Friendly Roofing Products
Our roofing products from Kingspan are certified ‘very good’ under BES6001, which is the standard certification for responsible sourcing of construction materials. They achieve this by using 15–20% recycled material, manufacturing in a 100% net zero energy factory, and having their own detailed EPD, which shows things like their zero ozone depletion potential, among other things. Please do ask us if you would like more in-depth detail on the insulation.
Sustainable Windows and Doors
Our windows and doors are made from either UPVC or aluminium, which are both 100% recyclable at the end of their life. They also embody the ‘fabric first’ ethos in that their energy-conserving properties and longevity of serviceable life make them good sustainable choices. These are coupled with high-performance, low emissivity double-glazed units which are filled with inert gasses and use warm edge thermal breaks to provide high levels of insulation.
Minimizing Waste in Construction
Waste is a huge problem in construction in the UK, which we are very aware of. We produce the absolute minimal waste possible by optimising all our materials through integrated design using available timber and sheet material sizes. The small amount of waste we do produce goes locally to our licensed waste transfer providers, who have a ‘zero to landfill’ target and recycle as much as possible at their 17-acre recycling facility.
Local Sourcing and Transport Efficiency
Our minimal wood waste goes into a separate container and the wood fibres are recycled into new materials. We source as much as possible locally to cut down on transport costs. When we do need to use suppliers from further away, we try to mitigate this by having large, infrequent deliveries to save on journey numbers for large lorries with only part loads. Both these policies cost us slightly financially, but we believe that it is worthwhile, and that we offset some of these costs by other efficiencies (such as the waste optimising).
Emission-Optimized Fleet Vehicles
We have invested in a fleet of new vans which all have the Euro 6 engines, meaning they’re the best they can be from an emissions’ perspective. Unfortunately, electric vans are not yet viable for the distances we travel and the loads we carry. We will, of course, adopt any new technology as it comes online. In the meantime, we continue to monitor advancements in green transport to ensure we’re ready to transition as soon as it’s feasible.
Tree Planting for Carbon Offset
As part of our ongoing environmentally responsible approach, we have recently partnered with an organisation called Tree Nation. They have sustainable tree planting projects both in the UK and around the world, and eventually, we hope to have a whole Sanctum Garden Studios forest! This partnership allows us to actively contribute to global reforestation efforts while supporting communities and biodiversity in the process.
Our Tree Pledge
We have pledged to plant one tree for every garden room we sell, so this will hopefully be 130–150 trees per year. We are starting our forest with ourselves planting 50 Japonica trees in a reforestation project in Nepal which is designed to improve local livelihoods and provide vitally important animal habitat. It will also offset 40,000 tonnes of CO2, which we think is amazing! Follow the Sanctum Forest here.