All of our projects feature some level of 'eco-design' - it's essentially what we do.
However, there are a range of approaches and client requirements, from the minimum energy performance to satisfy Building Regulations, to the gold standard of passivhaus, and the use of low impact materials.
Some years ago, we wrote these 'lessons for eco-design', and while technologies and energy sources change, the basic principles hold true
eco design principles
we have been practicing ‘eco-design’ since long before words like sustainability and carbon emissions were commonplace -although the details are complex, the principles of ‘green’ ‘eco’ ‘sustainable’ architecture are simple:
1 : insulation, insulation, insulation
the first principle of eco-design is to insulate as much as possible - working to the passivhaus standard requires a u-value of ± 1.0 for the major elements of the building
2 : airtightness
in recent years we've learned the importance of good airtightness, in order to avoid draughts + control ventilation - the passivhaus standard seeks to reduce this to 0.6 ac/hr
3 : comfort ventilation [mvhr]
in order to achieve good + healthy air quality, a central mechanical ventilation system is normally used, which can be made extremely efficient by adding a heat recovery unit
4 : passive solar
we seek optimal passive solar gain, balanced with shading to avoid summer over-heating [we’ve all been fried inside conservatories in June] - passive solar depends on site, shading + orientation
we favour the ‘fabric-led’ approach, i.e. spending most effort on the basics of insulation, airtightness and comfort ventilation, but clients are increasingly interested in the ‘active’ aspects of eco-design...
5 : active solar
photo-voltaic + solar heating panels generate electricity + hot water. whilst these have longer pay-back periods than the passive approaches, the capital costs are reducing along with their cost, and solar installations are becoming nearly standard
6 : micro-generation
with the introduction of government subsidises via FiTs [feed-in tariffs] and RHI [Renewable Heat Initiative] the various forms of generating electricity - PV’s, wind power,, hydro-electric are rapidly becoming more economically viable
7 : biomass | heat pumps | geo-thermal
biomass heating is increasingly seen as a less sustainable and more polluting source of heating.
heat pumps [both air-source and ground-source] have attracted huge public attention in recent years, but their efficiency and that of the building need to be carefully considered
we are now designing 'all-electric buildings, in readiness for the further de-carbonisation of the grid - almost inconceivable to eco-designers until the last few years