Step by Step Retrofit
Case Study
We’d lived in Parklands for 16-years before we finally began construction. The time was never quite right to move out and put everything else in life on hold for a year or more. So in 2020, we opted for a phased approach. In addition to allowing us to continue to live in the home we loved, the step by step approach allowed us to take on the day to day management of the project while still doing the day job, complete an MBA, ace 6th form and occasionally squeeze in a little bit of a social life. As a step by step approach makes the overwhelming manageable and financially viable. Right now we are at phase 2c.
A Whole House Plan
We had a very clear vision of what we wanted for our home. It had to achieve at least EnerPHit Plus certification, reusing material wherever possible and push forward understanding, while remaining a family home that fitted with the local setting in a sustainable way. The house itself was perfectly suited to a radical retrofit, built in 1977 it still had it’s original windows and cladding, a dated kitchen and a layout that didn’t suit life in the 21st century.
Alan translated this vision into a whole house plan, including planning documents and a detailed energy strategy. It was important to be clear about the final goal before considering sequencing to ensure that the full potential of the project is achieved, avoiding costly (carbon and financial) redoes. The plan allowed implications of each decision to be understood and properly planned.
Breaking the project into steps, each with smaller bite sized activities was a relatively simple process, like goal setting. Alan grouped together and ordered tasks to reduce complexity and costs while maintaining comfort. Having the first floor extension, roof, external cladding and first floor windows all completed during the first step reduced the need for moving windows and meant that we would only require costly scaffolding once. As the windows opened inwards to optimise external insulation on the first floor and outwards to optimise internal insulation on the ground floor, the windows had separate delivery costs so were easily split into 2 phases. During this phase the ground floor of the house remained an untouched, relatively clean respite at the end of the day.
In keeping with good goal setting principles we started with the end goal and worked backwards. Our final step will be the heat pump installation, but only if we need one due to the experimental innovative roof panels. With the help of PHPP analysis we already know what size we’ll need and that is important as it’s had implications for work at each other stage. Every floor will have been up by the time we purchase the heat pump and the bathrooms will have been tiled. There is no way we want to be cutting through the new floors or calling back the tiler because a radiator needs changing. As we’ve moved through the project radiators have been removed, relocated and resized, optimising the heating strategy ahead of the installation of the pump. And don’t worry we haven’t been cold, the home is already warmer and more comfortable then it has ever been.
Time to think and breath
All retrofit projects throw a curve ball your way, sometimes the structure is hiding something you didn’t expect or it might be a supply issue. Mostly our jaw-droppers were Covid delays, or associated with innovative tech we are trialing. The phased nature of the project meant that there was no requirement for a snap decision or pressure to change the spec when an issue arose, we had the luxury of time to either wait or explore the implications of potential changes. We also had time to regroup and recharge before the next phase started.
Programming our phases to allow us to continue to live comfortably in the house saved on relocation and rentals costs. And living and working in the building during the work has had immeasurable positive benefits, though the dust will always be a negative. When one of the trades had a question, we were there to answer. When a carpenter put the door in the wrong location or fitted the wrong window, we were able to spot the issue early, ensuring corrections were made without any compromises. It also helps to keep motivation high, when you see the new window opening for the first time, wow!
It’s easier on the finances
There are additional costs associated with phasing a build, there are extra working drawings for holding details and you’ll be paying higher home insurance premiums for longer. Though there are savings too, undertaking a stage only when funds become available avoids interest charges on loans. But it’s the additional control over your cashflow that is the greatest benefit of a step by step retrofit, as you’re committing to much smaller figures, it’s so much less stressful.
Without the pressure of having trades on-site you have time to shop around for the best deal. You’re not paying a premium to get a plasterer in today or pay the electrician to sit around on site tomorrow. Time means that we got our preferred professionals, the people who know what they are doing, and do it right first time. However the trades may need to come and go more which is not necessarily as efficient as a retrofit in one go, so can increase costs – good planning can offset this.
We’ve saved a lot of money on airtightness taping. It’s time consuming but not specialist work, actually with a little training generally you’ll make a better job of it on your own home than perhaps someone less invested in the project. We completed plaster boarding and taping before arranging for our plasterer to come back in. This way we don’t have to panic if something else distracts us. Then when we’re waiting for him to be free we have time to prep for the next step.
Our top tips for a step-by-step retrofit
Definitely have a whole house plan as it’s vital to see where you are. You don’t need to slavishly follow the predetermined route, it’s great to have a scenic diversion as long as you know where the diversion is going to take you. We made some changes to our internal wall insulation, the Siga Marjrex, single directional vapour control layer wasn’t available when we originally wrote the plan but it’s cactus like properties mean we can have a lot more internal insulation.
Put the MVHR unit in early to start benefits for improved air quality as soon as possible. As your home stops being so leaky you will need to take control of you ventilation. Given the benefits of fresh filtered air in every room it makes sense to do this as early as possible. You will need to proactively manage the system, turning it off when someone is making a lot of dust and you’ll likely need to change your filters more often. But it’s worth it, as in addition to the fresh air your plasterer will love it and odours are managed. As one of the items that effects every room of the house it’s also easier to get it installed early.
Build in meaningful breaks to recap and refuel. We’ve planned breaks around exams and special events.
Embrace the dust (still working on this one). No mater what you’re doing there will be dust, mucky footprints and disruption, so plan for this. Don’t install delicate surfaces early on and leave flooring finishes until later stages.
