Scottish architecture studio Loader Monteith has completed the extension and renovation of a traditional red sandstone terrace house in Glasgow, known as Old Red House, for medical doctors James Morton and Fenella Barlow Pay. Described by the architect as a “sustainable prototype for historic homes”, the project transforms the late 19th century property into a highly efficient, low-energy family home. Food author James and his wife Fenella have reworked the end-of-terrace house into an exemplar of sustainable retrofitting and hands-on craftsmanship.
The brief
From the outset, the project focused on improving ground-floor spatial use, removing gas as an energy source, strengthening the connection to the garden, and prioritising high environmental standards and natural materials. Drawing on Loader Monteith’s Passivhaus and energy-efficient design experience, the clients sought to demonstrate that traditional terrace homes – which make up 25 percent of the UK’s building stock according to the 2021–2022 English Housing Survey – can achieve strong environmental performance.
Transforming the existing structure
The late 19th century house was structurally sound but suffered from poor insulation, disconnected interiors, and energy-intensive systems. Preserving the charm of the original structure while prioritising contemporary living standards, James and Fenella stripped the house back to its brickwork. Through a carefully considered rebuild, they added a new ground-floor extension that accommodates the kitchen, living, and utility spaces.
An underused 1970s side extension was retained and refurbished. It now forms a bright open-plan living area connected to the new kitchen by an original stone wall which marked the former exterior. The wall incorporates a double-sided fireplace, creating a central family space with a sense of openness and a subtle separation between areas.
Corten steel and burnt larch extensions offer direct access to the large rear and side gardens. The family maintains a flourishing kitchen garden, alongside a greenhouse made from salvaged glass and mature pear and apple trees.
Craft, materials, and self-build elements
Much of the finishing work was completed by James and Fenella, who sourced environmentally friendly materials and undertook extensive insulation. The kitchen, designed and CNC-cut by Fenella after researching 3D design, is made from birch plywood finished with dark Indian Ink. James, a finalist in the 2012 series of The Great British Bake Off, tasked Loader Monteith with delivering a pragmatic layout tailored to baking, proving, and brewing, supported by a generous kitchen island and an adjacent utility space.
Technical strategy
Loader Monteith’s spatial and material strategies established the basis for energy-efficient upgrades. Breathable wood fibre insulation, natural lime plaster, and non-toxic finishes contribute to a healthy indoor environment. Broached fair-faced stone on the extension aligns with the original sandstone, while charred larch cladding, a green roof, and high-performance glazing reinforce the environmental aims.
Energy performance
James installed thick insulation across floors, walls, and roof to reduce heat loss and improve moisture regulation, using an infrared camera to identify areas requiring attention. An efficient air source heat pump supplies warmth through upgraded cast iron radiators and operates three to six hours per day. Coupled with smart tariffs, this reduced the family’s energy bills to less than a third of previous levels. Guided by Loader Monteith, the project applies Passive House principles in a practical manner suited to typical UK heritage homes.
Planning and conservation context
Despite the home’s position in a conservation area, the project secured approval for solar panels, with Loader Monteith leading the case on environmental grounds. Old Red House became the first in the area to gain such approval.
James Morton said: “When we undertook the project, we looked into the models for making a house sustainable. Passivhaus and EnerPHit are incredible yet largely inaccessible to the average DIY’er, so we used the project as an opportunity to see if a fairly common old home could be taken very close to net zero, and still be a comfortable, beautiful space to enjoy as a family.”
Matt Loader, Director at Loader Monteith, said: “James and Fenella were very clear on their brief from the outset: to create a sustainable, stylish home. We are facing many crises to housing and the environment in the UK, and Old Red House is a testament to the changes we can collectively make to play a small part in addressing these. A home that someone loves and will look after is inherently more sustainable — Old Red House will doubtless be well loved into the future.”
Old Red House shows that comprehensive retrofits are possible within conservation areas while meeting contemporary energy standards. The project offers a practical model for upgrading characteristic terrace homes, balancing heritage and performance in ways that can be applied elsewhere in the UK.
