Mass timber structures
Frames, floors and cores in cross-laminated timber and glulam, up to 12 storeys, in place of concrete and steel.
41 timber-framed buildings completed since 2016
General contractor for commercial, housing and infrastructure
Buildings that give back more than they take.
Halden builds offices, homes and public buildings in timber, with planted roofs and their own power, at close to the cost and programme of a conventional build.
- 62% less embodied carbon than a typical build
- 38 buildings generating their own power
- Every project carbon-measured, from first delivery to year two
Our carbon numbers
Measured, not promised.
We count carbon from the quantities actually delivered to site, not from design-stage estimates, and an independent assessor checks the model before handover. The operating figure comes from two years of metered energy use, projected over 60 years.
- Materials
- Construction on site
- 60 years of operation
Typical new building1,500 kgCO₂e/m²
Materials 520 · Construction 80 · Operation 900
A Halden building408 kgCO₂e/m²
Materials 190 · Construction 38 · Operation 180
73% less over the building's life. Materials and construction alone come to 228 against 600, which is 62% less. Halden figure: average of our 14 buildings with two full years of meter data. Typical figure: benchmark for a concrete-and-steel building of the same type and size.
How we get there
Four things do most of the work.
None of them is experimental. We have built each one dozens of times, and we price them in every tender.
Living roofs and facades
Planted roofs and balconies hold back storm water, shade the building in summer and protect the roof membrane.
27,400 m² of roof and facade planted to date
On-site solar and heat pumps
No gas connection. Roof arrays and heat pumps cover heating, cooling and hot water from day one.
6.2 MWp of solar installed across 38 buildings
Reused and low-carbon materials
Reclaimed steel, cement-replacement concrete and recycled aggregate, each logged in a materials passport.
34% of materials by weight reused or recycled, on average
Projects
Every building leaves with a carbon label.
Like the label on a fridge, but for the whole building. The figures come from delivery records and meters, and we publish the ones we are less proud of too.
HousingAlder Court
Carbon label Checked at handover
ABC
Carbon rating A
- Embodied carbon
- 212 kgCO₂e/m²
- Timber in structure
- 71%
- Energy use
- 38 kWh/m² a year
- Generated on site
- 41% of annual use
CommercialMill Quay Offices
Carbon label Checked at handover
ABC
Carbon rating A
- Embodied carbon
- 236 kgCO₂e/m²
- Timber in structure
- 64%
- Energy use
- 52 kWh/m² a year
- Generated on site
- 61% of annual use
PublicFernhill Primary School
Carbon label Checked at handover
ABC
Carbon rating B
- Embodied carbon
- 268 kgCO₂e/m²
- Reused or recycled material
- 48%
- Energy use
- 44 kWh/m² a year
- Generated on site
- 104% of annual use
InfrastructureHarrow Lane Interchange
Carbon label Checked at handover
ABC
Carbon rating C
- Embodied carbon
- 412 kgCO₂e/m²
- Reused steel and aggregate
- 37%
- Energy use
- 58 kWh/m² a year
- Generated on site
- 28% of annual use
Concrete platforms kept this one at C. We publish it anyway.
Read the Harrow Lane carbon reportRating bands, embodied carbon in kgCO₂e/m² (materials plus construction): A under 250, B 250 to 400, C 400 to 550. A typical new building sits near 600.
A roof can be a park, a power station and a rainwater tank. We build it to be all three.
Process
From brief to a building that runs itself.
One team and one contract from the first carbon model to the last meter reading.
Measure the baseline
We model your brief as a conventional building first, so every later saving has a number to beat.
Weeks 1 to 3
Design the carbon out
With your architect we test frame, facade and services options, and price each one in money and in carbon.
Weeks 4 to 14
Build it clean
Frames arrive prefabricated, site plant runs on electricity, and every delivery is logged against the carbon budget.
9 to 16 months on site
Monitor it for 2 years
After handover we meter the building, tune the systems each season, and send you the real figures every quarter.
24 months, included in the contract
Costs and time
Slightly more to build. Much less to own.
Averages across our last 14 completed projects, each measured against the conventional tender for the same brief.
- +1.8%
- build cost, repaid in 6 years of energy savings
- 5 weeks
- shorter on site, because timber frames arrive cut to size and go up dry
- −58%
- energy bills, metered over the first two years of occupation
Where it does cost more: planted facades need two maintenance visits a year. That is priced into your quote, not discovered after handover.
“Halden's tender came in 1.6% above the concrete option and we let the building five weeks early. Two years on, the energy bills are less than half what our other offices pay.”
Request a quote
Get a price and a carbon figure for your project.
Send the brief, or just the site and floor area. Within five working days you get a budget cost, a programme and a carbon estimate, set beside the conventional option.
- Call the estimating team
- 020 7946 0135
- Head office
- 14 Wharf Row, Northbridge NB1 4HT
- Hours
- Monday to Friday, 8:00 to 17:30