what makes a sustainable home?

By David Caldwell

We are currently working with Tiny House Community Bristol on the UK's first Tiny House Co-Housing project. The group have very high ambitions for sustainability for the project, but what really makes a house sustainable?

Perhaps the key to sustainability is technical, for example thermal perfomance or embodied carbon? Maybe it’s social; affordability, fair forms of tenure and the house's ability to adapt to changing circumstances and cultural needs over time? Or could it be something more emotional - if a house is loved, surely it is more likely to maintained and well used for decades to come? It is all of the above and much, much more, but sometimes these things are conflicting and difficult decisions have to be made.

We have been undertaking a design exercise for each of the different Tiny Houses in the project to explore how to maximise the future potential for adaptability so that the houses are able to change as the residents’ needs change, or as new residents move in. The floor plans shown below demonstrate a few of the potential layouts for one of the houses.

One of the design options which unlocked this number of plan variations is to have a relatively large number of windows on the rear (north) wall. Alongside this design exercise, fellow members of the design team over at Buro Happold have been undertaking Passivhaus modelling to ensure the thermal performance of the houses is optimised. They have recommended that the north-facing rear windows are removed because lots of heat is lost through north facing windows without any solar gain to top the house's temperature up again.

So what is more important for a house to be truly sustainable - that it requires as little energy as possible to heat, or that it is able to adapt over time? Let us know your thoughts in the comments! Hopefully with more design development we will be able to strike balance between these issues and achieve an adaptable, Passivhaus-standard home.