When you build anything that takes away amenity space or removes part of your living garden it’s always preferable, for very many reasons, to replace what you’ve taken away.
If you’re going to create a garden room unless you’re building off an existing hard stand you’re very likely building right where grass or other greenery is established or even just plain old earth. In any event the flora and fauna will be destroyed with no chance of ever returning while the structure is there.
I’ve come across two ways of getting over this.
The first is to build the room off a steel frame that is raised from the ground allowing animals and birds access below without damaging the new structure. You can even expect some greenery to flourish, not as well as it did, but good enough to absorb CO2 and provide living space for worms, beetles and other insects. See the fab nodigging.co.uk people for details.
And the other way is to replace the area lost with precisely the same area but on the roof.
Living roofs are easily maintained, fantastic for wild life and are environmentally superb ways of encouraging beetles, bees & butterflies. It’s a doddle to introduce worms to them and if you’re clever you can harvest excess rain water that can be reused on the roof when it gets dry. Look for sedum, succulents and other Crassulaceae in either seed form or as a turf.
If you have a sedum turf supplier local to you, and few of us do, then it’s best to ask them to provide the whole kit which will easily be installed on our garden room roofs as we only use GRP which is impervious to water. Triple felt will not support a living roof as the permanent prescence of damp earth will rot the material.
Expect to pay about £1,000 for a 4m x 2.5m roof area including the retaining sides. If the supplier has to drive 300 miles in a fossil-fuel powered lorry to get to you then the CO2 creation is a serious issue I’d suggest so better to buy your own medium and plant seeds. The eventual effect will be the same but it’ll take a few months to establish.
Is there another way I haven’t thought of to get back that green space you lose when building new structures?