June 28, 2026 / By rachel
Some projects have unusual beginnings and this one started with RRA’s Mark Powles telling a young developer that he didn’t need an architect for his project. Unusual sales technique, granted.
For Week 17 of our 40 Projects in 40 Weeks series, we are revisiting Vespers, a contemporary Cheltenham SIPs house from 2019.
It is also a nice follow-on from last week’s blog about what is believed to be the first SIPs house in the UK. By the time Vespers came along, SIPs construction was more readily available, but still not exactly everyday housebuilding territory.
A bit of advice remembered
The story begins a few years earlier, when the client contacted RRA about a small terraced property in Cheltenham. Mark visited the property, talked through the plans and advised that, for what the client wanted to do, he did not really need an architect. Rather than dressing it up into a bigger job, Mark offered to be available for a bit of free advice if needed, just to help a young business get moving.
The client appreciated the honesty and said he would remember Mark when a bigger project came along.
And he did. A couple of years later, he called Mark and asked if he would look at an old, run-down bungalow with him to assess the potential.
Tight site, big ambitions
Mark and the client both agreed the bungalow was not worth keeping, but the site itself had real potential; tucked away, private and well suited to a well-designed new build. The client himself had a good eye for design and he wanted something more interesting than a standard developer house, whilst also delivering strong energy performance on a very constrained site.
However, not only was the site very tight, the access to the site was extremely restricted, through a narrow residential lane. This was not a site where you could just turn up with a large lorry and hope for the best. The team had to plan carefully, coordinate properly and make the build process work within the limits of the site.
After considering various options it was clear that this was a project where SIPs construction would be ideal. Structural Insulated Panels are manufactured off site and then assembled quickly on site, which helped reduce the construction period for the building envelope. It was still a tricky process, with machinery needing to access the site and panels being craned carefully into position. However, it was very successful and the SIPs construction was completed in just 23 days from damp proof course. Impressively quick.
A house with performance and personality
The whole house was designed to be energy efficient, airtight and well insulated. The SIPs system helped create a high-performance envelope and the house includes MVHR (Mechanical Ventilation with Heat Recovery) to manage airflow while reducing heat loss.
The design has plenty of personality too. The first floor is finished in dark timber cladding, while brick slip cladding at ground floor level helps the house sit more comfortably alongside the surrounding buildings. Large areas of Crittall-style glazing flood the space with light and gives the house its distinctive contemporary character and great connection to the garden.
Inside, double-height spaces, clean detailing and a strong visual connection to the outdoors help make the house feel far larger and more open than the original bungalow could ever have managed.
SIPs, and a nice full-circle moment
One of the interesting things about Vespers is that, by this point, SIPs had moved from pioneering idea to practical construction choice. The system offered speed, accuracy, insulation and airtightness, all of which suited the project. Working with Glosford SIPs, a Hereford-based SIPs specialist using Kingspan TEK wall and roof panels, the construction method helped turn a difficult site into a buildable and high-performing new home.
And this is where the story links rather neatly back to last week.
In our Week 16 blog, we looked at what is believed to be the first SIPs house in the UK, designed by RRA Architects with Oakwrights in 2000. That project involved a SIP panel sample brought back from America by Oakwrights’ Tim Crump, which sparked a chain of events that led to Kingspan TEK becoming a major name in SIPs construction. Fast forward to 2019 and RRA was once again designing with SIPs, but this time the system had become established, available and technically proven.
Not quite time travel, but definitely a satisfying circle.
Vespers is a great example of how good relationships can grow from honest advice. The first conversation did not turn into a project, but it turned into trust. A few years later, that trust brought the client back to RRA with a bigger opportunity and a much more ambitious brief. The result was a striking Cheltenham SIPs house, built on a challenging site, with a developer client who wanted to do something properly.
You can see lots more photographs on the Vespers project page and click to find out more about Glosford SIPs.
This project is part of our #40Projects40Weeks series, celebrating 40 years of RRA Architects through some of the projects, people and stories that have shaped the practice. If you have missed any of the previous posts, you can catch up on our News page.
About RRA Architects
Currently celebrating its 40th year, RRA Architects is an award-winning architectural practice established in 1986, supporting clients across residential, commercial, retail, development, heritage, education, community and conservation projects.
We work nationally, but are mostly focused across Gloucestershire, Herefordshire, Shropshire, Worcestershire, the Cotswolds, Bristol and Avon, the West Midlands, South West and South Wales, helping clients create thoughtful, practical and well-designed buildings.