Knowledge Centre
Blogs, FAQs, technical downloads and guided journeys — everything you need to understand insulated raft foundations.
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Self-Builders
First principles, costs, and getting started on your self-build project.
Start journey →Architects
Thermal data, CAD details, specifications, and RIBA stage guidance.
Start journey →Timber Frame Companies
Precision tolerances, thermal performance, and trade partnership.
Start journey →Builders & Developers
Programme savings, compliance, and cost comparisons at scale.
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Passivhaus Leisure Centre Foundations: What to Resolve During Pre-Construction
A practical checklist for coordinating structure, insulation, pool interfaces, moisture protection, thresholds and services before construction.
Building with Timber Frame or SIPs? What to Agree Before the Foundation Is Built
Seven points for the architect, engineer, wall supplier, foundation supplier and contractor to resolve before the foundation is built and the wall package is manufactured.
Scotland's Proposed Passivhaus Standard: What Designers and Builders Need to Know
What the Stage 2 consultation proposes, why its name is being debated and what project teams should consider before the 16 October deadline.
Hackney Targets 197 Passivhaus Homes: Why Early Design Coordination Matters
Hackney targets at least 197 Passivhaus homes. What can architects and developers take from its early design coordination?
How to Reduce Thermal Bridging at a Floor Slab Junction
How coordinated wall, slab-edge and structural design can reduce additional heat flow at a foundation junction.
Insulated Raft Foundation Installation: The Construction Sequence Explained
The sequence from ground preparation and services through insulation, membranes, reinforcement and concrete.
Insulated Raft Foundation Details: 5 Junctions to Resolve Before Construction
Five wall, threshold and service interfaces architects should coordinate before the raft is detailed and poured.
Why Repeatability Matters in Large-Scale Construction
What the University of Staffordshire Student Village shows about repeatable details, predictable interfaces and designing for consistent delivery at scale.
Guy Martin's House Without Bills: What a Passivhaus Retrofit Tells Us About New Builds
What the Channel 4 programme shows about the order of work in a retrofit, and why the ground floor is the part you cannot easily fix later.
Passivhaus at Scale: What Weavers' Hall Tells Us About Early Design Coordination
What a 459-bedroom Passivhaus development teaches us about early contractor involvement, technical interfaces and resolving details before site.
What Is the Best Foundation for a Passivhaus Home?
Why the wall-floor junction and its Psi-value matter more than choosing a foundation type by name.
What Foundation Should I Choose for My Self Build?
How ground conditions, energy targets and programme should shape your foundation choice.
What Rising Energy Bills Mean for the Business Case for Fabric-First Design
Why low energy demand, smaller heating equipment and durable running-cost claims matter more as energy prices rise.
Why Housing Associations Are Choosing Passivhaus Before They Are Forced To
Lower tenant bills, reliable performance and fewer retrofit liabilities are making the case now.
Insulation Below vs Above the Slab
How insulation position changes thermal mass, comfort, and performance.
Insulated Raft Foundations Explained
A practical primer on how insulated raft foundations work and where they fit best.
What is an insulated raft foundation?
An insulated raft foundation is a reinforced concrete slab that sits on top of a layer of load-bearing insulation, with more insulation wrapped around its...
What Determines Concrete Slab Thickness in an Insulated Raft Foundation?
There is no universal minimum concrete thickness for every insulated raft foundation. The slab must be designed for the building loads, ground conditions,...
Technical Details (PDF Library)
Typical Section
All
Standard Edge Detailing
All
Edge & Base Combinations
All
Edge Details — Common Variations
All
Brick Plinth Detail
Brick & Block
SD-0022 — Brick Support, DPM Under Slab
Brick & Block
SD-0022A — Brick Support, DPM Above Slab
Brick & Block
SD-0022B — Brick Support, Waterproof Concrete
Brick & Block
Solid Aircrete Wall with EWI
Brick & Block
Hollow Clay Blocks Detail
Brick & Block
Timber Frame & SIPs Wall Junction
Timber Frame, SIPs
Larsen Truss Detail
Timber Frame
I-Stud Twin Wall — Dual Bearing
I-Stud
Twin Wall I-Stud — Inner Bearing
I-Stud
Sole Plate Location Guidance
Timber Frame
ICF Wall Detail
ICF
Wood-Cement Fibre Blocks Detail
Brick & Block
Slate & Tile Edge Detail
All
Party Walls Detail
All
SD-0023 — Threshold Detail
All
SD-0031 — EM10 Threshold Support
All
SD-0032 — EM15 Threshold Support
All
SD-0033 — EM20 Threshold Support
All
ISOQUICK Threshold Support Brochure
All
SD-0018 — Drains and Ducts
All
SD-0015 — External Tanking
All
SD-0003 — General Sub-Base Arrangements
All
Stepped Footing — Large
All
Stepped Footing — Small
All
DPC & Full Radon Protection
All
Underfloor Heating Options Guide
All
Installation Guide — Part 1: Groundworks
All
Installation Guide — Part 2: ISOQUICK Installation
All
Installation Guide — Part 3: Brick Support System
Brick & Block
ISOQUICK Brick Support System — Introduction
Brick & Block
ISOQUICK Brick Support System — How It Works
Brick & Block
IQ Technical Specification
All
IQ-60e U-Value Tables
All
IQ-90 U-Value Tables
All
IQ-210 U-Value Tables
All
Kiwa BDA 3rd Party Certification
All