Victoria Park House, Hackney, London
In the context of an escalating climate emergency, the construction industry occupies a problematic positions. The traditional growth of the industry has been based on the demolition of old buildings and the replacement with new yet this process consumes vast amounts of energy and needs to be effectively challenged if we are to stand a chance at reducing emissions as planned.
Until recently the construction industry’s sustainability focus has been on reducing the energy consumption of the buildings themselves rather than the consumption of the industry as a whole. Buliding Regulations along with rating standards such as BREEAM and LEED have encouraged and enforced an increase to the performance of building fabrics and efficiency of heating and cooling systems. These changes have reduced the emissions relating to the running of buildings but leave the problems associated with emissions relating to the creation ion buildings in the first place.
It is estimated that the construction industry is responsible for between 35 an 40% of the UKs total carbon emissions. This is mainly as a result of the energy embodied in the production of construction materials, many of which require high levels of energy to produce. This problem is then exacerbated by the industry’s economic model which favours demolition and re-building when a building reaches its perceived life-span. The embodied carbon ends up wasted in a landfill and the cycle repeats.
Given this context, it’s not surprising that campaigns encouraging refurbishment in place of demolition are gaining ground. There is an obvious argument to keep existing structures wherever possible and to focus design skills on inventive ways to re-position and re-use existing buildings rather than conceiving new ones.
Lowe Campbell,Edwards, Detroit- Stripping back and exploiting whats already there
Republic - Having been stripped back to its structural basics the the Import Building was expanded and repositioned with a new internal atrium constructed from structural timber - a sustainably sourced material that also helped to offset the severity of the exposed concrete elsewhere
#1 - The Quandaries of Refurbishment
Although the benefit of refurbishment over demolition seems obvious, the actual process of doing it, is full of choices and questions that require careful consideration. Fundamental to these is the extent of refurbishment proposed. The definition of refurbishment can vary from a simple redecoration, to a complete strip back to the frame and foundations. In sustainability terms deciding on where on this spectrum to place the project will mean balancing the potential energy consumption of the building with the potential energy consumption of a refurbishment. Doing little to an existing building will produce little embodied carbon in terms of construction work, but if that building has an inefficient envelope and heating system then the limitations of the refurbishment will mean the building continues to emit substantial carbon through its operation. Conversely stripping a building back to is bare bones and introducing new external walls, roofs, glazing and services will help create an efficient low emission building but will embody far more energy in its construction.
How this balance sets will depend on the particular characteristics and context fo the building being refurbished. How well does it currently perform, what is it made of, where is located ? The approach to a concrete framed building with extensive single glazing, limited insulation and antiquated services will illicit a different response to a building that is well insulated with newer and more efficient systems. Taken to extremes, the realities of refurbishing an old building to the highest of modern standards can mean effectively replacing everything save the primary structure, and if this structure in itself is not optimal - ie it is badly orientated or its plan cannot accommodate well the proposed use, the feasibility of refurbishing at all comes into question.
On top of this will be commercial considerations. Refurbishment is attractive and viable because it is in the most part cheaper and quicker than demolition. As a refurbishments scope increases so does its costs, adding another balance to the equation. Current building regulations allow for lower standards of thermal performance in refurbished buildings compared with new builds along with a lower expectation in terms of sustainability standards. To commercial, profit driven developers there is therefore little incentive to spend on increased thermal performance when increased returns are more visibly derived from spending on re-branding and aesthetic make-overs. This does not bode well for the large-scale reduction in carbon emissions proposed by the Paris Agreement.
Ningbo History Museum by Wang Shu with its poetic used of relaimed masonry used to form the external walls
#2 - The Future
If we are to meet expectations, all existing buildings need to be retrofitted to meet high thermal performance standards. This means a replacement of all gas fired builders, all single glazed facades, added insulation to solid facades, replacement of antiquated curtain walling etc. How this can be achieved with low embodied carbon is a challenge to manufacturers and designers. How this can be achieved commercially is a challenge to politicians as it will require clear fiscal incentives and changes to regulations to change the current mind-set.
See our Retrofit Sustainability Strategy