Octogenarians Keith and Ann Lewis’ new home was not just a labour of love, but a real family affair, with the couple engaging the services of their son and daughter-in-law to create a self-build that combines barn-inspired architecture with ecology-friendly technology

TEXT JESS UNWIN IMAGES CHRISTOPHER TERRY PHOTOGRAPHY

Mark and Jess Lewis have succeeded in providing a place for Mark’s elderly parents to live at the bottom of their garden – but to call it a granny annexe would be a million miles from the truth, and do no justice at all to the remarkable eco-friendly home they’ve helped to create.

That new home caters perfectly to the needs of Keith and Ann Lewis, who are both in their eighties, yet also features a spectacular double-height central space, plus heating and power solutions with impeccable ‘green’ credentials.

What’s more, this building is not quite what it seems, with walls erected using structural insulated panels (SIPs) – still not quite a mainstream construction method in the UK – and clad entirely in brick slips.

The house is not really at the bottom of Mark and Jess’s garden either. Instead, it’s in one corner of three acres of land in the Nottinghamshire village of Normanton on Trent. Three acres that include the couple’s own Grade Two-listed 18th century home.  

The new 21st-century self-build addition comprises a central block with an open-plan ground floor, where the kitchen/dining space flows into the double-height main living area. Here, the north-facing wall is almost entirely glazed, with two sets of French doors and windows above. 

Striking open-tread oak stairs take you to the mezzanine-style first floor, which sits above the kitchen/dining space, and is currently part office, part home gym. With the double-height space stretching to the apex of the roof, it’s abundantly clear the architecture deliberately echoes agricultural barn design.

Off the main living area are two ground floor wings. The west wing contains a small plant room, family bathroom and two bedrooms, one of which is currently being used as a snug. The main (ensuite) bedroom for Keith and Ann is in the smaller east wing, across the hallway from the south-facing main entrance. 

It was in 2017 that a plan was first hatched to build a new home for Mark’s parents, who at the time were living in a bungalow in Llanhilleth, a village about 15 miles north of Newport in south Wales.

The key design goals were clear. Ann says: “Besides the space and light we didn’t have at the bungalow, the initial idea was a house with two bedrooms and open-plan living areas all on one level, in case of any future mobility issues we might have.”

Almost all of Ann and Keith’s completed new home, which they moved into in April 2022, is indeed on the ground floor, but how has it come to include the double-height space and mezzanine first floor?

Mark explains: “None of us knows what the future holds. We were building it for my parents, but Jess and I were also wondering if it might be something we might live in at some point.

“We’ve lived in barn conversions before and loved the open space of the double height. Our architect really bought into that idea early on so that design feature is myself, Jess and the architect, while the rest of it is down to my parents. Overall, it’s an amalgamation of all of us really.”

Ann says: “It’s bigger than we originally expected but that’s a bonus and I love it as it is.” She adds: “It’s good to know that when our days are done Mark and Jess have something that will be a sellable asset or that they can live in themselves.”

Everyone’s happy with the end result of this self-build project but getting to the finishing line – finally crossed with Building Regulations sign-off in January this year – was not always straightforward.

The plot the house now sits on was previously partly occupied by two old cottages, which the local planning authority originally wanted Mark and Jess to renovate instead of building something new.

Uninhabited for decades and structurally unsound, the cottages weren’t viable for renovation. The planning authority agreed they could be demolished, but also decided that the SIPs structure of the proposed new build would have to be clad in brick slips.

“That was a major issue for us,” says Mark. “Not only did it increase the costs by £15,000 but we wanted to go with a timber clad because the design was barn-inspired. Timber would have been a third of the price and a lot quicker to put up.” 

The slips, effectively tiles glued to the SIPs, still needed mortar pointing like real bricks – an exercise that turned out to be an “absolute nightmare” and took close to a month, reveals Mark. The final brick-like render is now both convincing and attractive but cost £30,000 for the slips and labour.

However, everyone agrees the biggest challenge within this project was not the cladding, but the earlier, costly, problems with foundations. After demolition of the old cottages and general site clearance in spring 2021, it became clear that strip foundations for the new building were not appropriate and pile foundations would be necessary. 

“It was quite depressing,” says Mark. “It took us six months to find someone to do the piling, which in the end cost close to £20,000 more than the strip foundation quotation we’d had. It knocks your confidence, something like that so early in the project – you wonder if the rest of it is going to be similar.”

Construction proper began in October 2021. Happily, the SIPs used to form the core structure of this self-build provided a welcome fillip, by moving the project on at a rapid pace. Mark says: “From flat foundations to the full house in position with just open roof and rafters took just more than 10 days – so the speed of using SIPs was quite exciting.”

Why SIPs? Mark explains: “One underlying principle of this self-build was to keep energy bills low. My dad was already thinking about some kind of prefab approach and SIPs are both an efficient way to build and provide good insulation. At the time I was also working with a company specialising in this kind of construction, so it seemed the obvious way forward.” 

The panels, which simply slot together, are in this case a sandwich consisting of magnesium oxide board on the outside, with a thin layer of galvanised steel on each edge, and insulating polyurethane foam on the inside. This gives the panels a high insulating strength. The design of the interplay between the SIPs and elements like doors and windows also helps to cut heat loss – as does the insulated roof. 

Besides the insulation, it’s the ecological-friendly heating that helps to keep energy bills low with an underfloor system fed by a Daikin 6 kW air source heat pump. While an unobtrusive outdoor unit sucks in air, the ingenious exchange of heat between air and water happens in an integrated tank, which is tucked away in the plant room.

The pump is powered by electricity, and solar panels installed on the south-facing roof of the west wing which can produce 3.4 kW of electricity. This means that, at times, the house generates more electricity than it uses, and Keith and Ann are paid for any excess electricity they export to the National Grid.

Not surprisingly, being a director at Airway Group, which provides air conditioning, electrical and mechanical services, Mark has done the maths on the house’s heating system. The heat pump has an impressive coefficient operating performance (a ratio of useful heating to energy required) of well over 4.0. The annual electricity costs of Mark’s parents’ new home are about a third of those at a similar size of the house using the current capped tariff of 31p/kWh.

Underlining this house’s environmental credentials, there’s high-spec double glazing – plus it also boasts a mechanical (natural) ventilation with heat recovery (recycling) system. Not only does this control oxygen and CO₂ levels, it means the air going out heats the air coming in. There’s no air conditioning for warmer weather, but skylight windows in the double height roof of the main block should help to get rid of excess heat.

Mark and Jess had a “notional” budget of between £300,000 and £350,000 for this self-build project. In the end, the total build cost was £419,000. Mark says: “Unanticipated costs didn’t help but we also experienced the biggest rise in building costs this country’s probably ever seen. Without that hike I don’t think we’d have been far off our original figure.” There’s no mortgage on the self-build with the sale of Keith and Ann’s bungalow providing £200,000 and the rest funded by Mark and Jess.

Mark says: “I’m very pleased with how the new house has ended up. It still feels slightly unreal – did we actually do this? But really, my parents were so involved in the building that it feels like Jess and I just enabled it rather than being the ones who completely drove it.” 

Jess adds: “For me, it’s such a precious thing to have family around and it’s lovely that we’ve been able to give Keith and Ann this sense of security with a new house that’s really been a labour of love.”

The final word should of course go to the couple enjoying the benefits of this wonderful new home. Ann says: “Keith and I are so grateful to Mark and Jess – it wouldn’t have happened but for them.”

HIGH POINTS

“We sit here sometimes and think how lucky we are – the new house has made such a difference to us. For all of us, finally getting the stairs to the first floor was special. And the first time you’re up on the mezzanine you get a proper sense of what an amazing space has been created here.” – Ann Lewis

LOW POINTS

“Evidence of bats in the old cottages delayed their demolition and resulted in costs of up to £5,000 for various bat surveys. Another headache was the decorating that we did ourselves to save money. The double-height central area was a particular challenge, it’s more than 5 metres high and took us a week using a borrowed builder’s scaffolding tower!” – Mark Lewis

CONTACTS/SUPPLIERS

ARCHITECTS

Ellis Healey Architecture
damian(Replace this parenthesis with the @ sign)ellishealey.com
0113 3453090

PROJECT MANAGEMENT/BUILDER

Domestic Construction Services
peterhope(Replace this parenthesis with the @ sign)msn.com

AIR CONDITIONING AND MECHANICAL

Airway Group
www.airway-group.co.uk
info(Replace this parenthesis with the @ sign)airway-group.co.uk
0800 0564162

HEAT PUMPS

Airway Heat Pumps Ltd
Daikin Sustainable Home Centre
info(Replace this parenthesis with the @ sign)airwayheatpumps.co.uk
01480 831010

SIP SHELL CONSTRUCTION

Etopia Custom
leemcardle(Replace this parenthesis with the @ sign)projectetopia.com
01884 855000

WINDOWS & DOORS

Hardwick Windows Ltd
www.hardwickwindows.co.uk
scott(Replace this parenthesis with the @ sign)hardwickwindows.co.uk
0115 8556010

MARK’S TOP TIPS FOR SELFBUILDERS

• “Your relationship with your builder is so important. We know and trust our builder, which made the project a joy. Aside from the SIPs shell, the heating and some of the other mechanical stuff, his company did everything else, and we were totally in their hands.”
• “It’s tricky to envisage drawings in the real physical world: something can turn out to be bigger, or smaller, than you imagined on paper. So, work through every detail with your architect and try to visualise it, ask questions about the plans and keep revisiting them. Maybe think about 3D modelling – that might have helped us!”
• “This house is for my parents, so the fact they were in temporary accommodation nearby during construction was invaluable. My dad was involved in all the inside finishings and would visit the site every day, but if questions came up outside those visits, the builders could get answers from my parents very easily.” – Mark Lewis