When it comes to energy retrofits, the devil is in the detail—especially at the edges. Poor coordination between measures like wall insulation, loft upgrades, and window replacements can quietly undermine performance. At Tactical Energy Systems, we believe that great outcomes come from great detailing. A recent project in London provides the opportunity to highlight some key detailing considerations.
The Challenge: A Whole-House Retrofit
Our client wanted a comprehensive upgrade:
- Loft insulation
- Flat roof insulation
- External wall insulation to solid brick walls
- Floor insulation over an unheated garage
- High-performance window replacements
Each measure is powerful on its own—but if sequenced correctly and installed as a system, can achieve so much more.
The Tactical Energy Difference: Getting the Details Right
Wall and Loft Insulation Interface
Most contractors would stop insulation at the soffit, leaving a cold gap around the top of the first floor. TES ensured the soffit and fascia were removed, allowing insulation to reach the roofline and connect with the loft insulation—eliminating thermal bridging and maximising performance.
Existing soffit concealing the top of the wall. The installer originally intended to insulate up to the base of the soffit.
The revised detail to ensure full coverage of the wall, and consistent coverage between the wall and loft insulation.
The result – soffit removed and insulation to the top of the wall, ready to adjoin to the loft insulation behind.
Windows and Wall Insulation
Our client chose Velfac glazing with U-values as low as 0.8 W/m²K. TES coordinated the installation so the windows straddled the insulation layer, preserving airtightness and thermal continuity. We didn’t just install—we strategised.
.Balcony Roof Detailing
A raised roof for insulation risked creating an awkward 150 mm step at the balcony doors. TES challenged this assumption and worked with installers to achieve a 75 mm upstand—maintaining accessibility without compromising the waterproofing warranty.
What Clients Can Expect from TES
- Holistic thinking: We don’t just install—we integrate.
- Performance-first mindset: Every detail is considered to avoid energy loss.
- Client advocacy: We challenge impractical assumptions to deliver usable, high-performing spaces.
Thinking about a retrofit?
Let Tactical Energy Systems help you get the details right—because performance lives at the edges. Book a free, no obligation chat with their team. Book time with Ben Foster: Free, no obligation chat to see how Tactical Energy can help
