A defence of MEP engineering for healthy, comfortable and sustainable office buildings

A lot of the most difficult challenges for office design relate to the speculative nature of many developments. The end users of the space often only get involved with the building during the base build construction and, quite often, not until post construction. Therefore, the design team has to anticipate the needs of all potential tenants, rather than designing for a specific occupier, which inevitably leads to over specification.  

It would be great to have the opportunity to design a scheme that was willing to compromise on thermal comfort, using CIBSE TM52 as a framework to provide enough cooling to keep the building comfortable 95% of the time, instead of sticking to current methods of designing that seek to maintain 24’C internally no matter what conditions are like outside. But the risks to a developer to do so, without knowing who the end user will be, and knowing that this will be (another) potential hurdle to leasing the building to prospective tenants, is very real. So the additional works to justify the design, defend it against agent push back and provide them with all the information needed to then sell that design to incoming tenants isn't allowed for or factored into consultants’ fees.

Although MEP can sometimes account for as much as 60% of a project’s construction budget, that certainly isn't translated in the fees for the MEP designer. The continued race-to-the-bottom on fees has led to a commodification of design to try and maintain profitability, so most end up not having the time (i.e. fee) to go outside ‘industry standard’ designs.  

Daylight in offices can be tricky due their deep plan nature, which is often due to project viability and site constraint reasons. We could design buildings that were shallower in plan, but then they wouldn’t get built because it would cost too much on a £/m² basis. The love of floor-to-ceiling glazing doesn't help either, because from a daylight and overheating perspective, glazing below desk height isn't useful. So in a battle over a project’s glazing budget, if we are allocating allowance below desk height, this means that useful glazing above desk height provides less benefit. If all this glazing is really wanted, a good countermeasure would be for moveable external shading to become standard, so buildings can have lots of daylight when it’s needed without the solar gain penalties in summer.  

On the subject of the lack or limited reuse of MEP kit, one of the main considerations is the how buildings are maintained and operated in use. Would you buy a 15-year-old car with no MOT records or any proof of maintenance? No, but this seems to be the norm in the built environment. Maintaining a building properly is expensive, so it rarely happens.

I found it odd to be asked to do a condition survey for a client and be asked 'what can we re-use?'. I only pop to the site for half a day, but they’ve owned the building for 20+ years. They should be telling me what's good to re-use, what is working well and what's on its last legs! And even when maintenance is done, it often has a very narrow focus on individual system components. A person from the heat pump supplier comes out to maintain just the heat pump. Someone else comes out to look at just the circulation pumps, someone else to maintain the heating/cooling emitters. Almost no-one is taking high-level responsibility for maintaining the heating and cooling system as a whole

For MEP re-use and adaptability, building owners really need to adopt the MEP systems from the base build contractor and let tenants know how they can adapt the systems for their fit outs, but not just for the first fit out post PC, but also for the 2nd, 3rd, 4th and 5th re-fit of the space.

In conclusion, MEP designs can be more considered, crafted and tailored (look at some of our projects for examples), but the wider industry and economics still have a way to go before this is a common approach.