Self-Build Routes Explained

The three routes

There are three main ways to deliver a self-build project. Each is a genuine route, each is used successfully by UK self-builders every year, and each involves real trade-offs. The right choice depends on your experience, your budget, your tolerance for risk, and how much time you have available.

Route 1: Main contractor

You appoint one company - the main contractor - who takes responsibility for the entire build. They manage all trades, coordinate the programme, and supply or procure most of the materials. You deal with one point of contact. The main contractor takes the project from groundworks to practical completion.

Pros

• Single point of accountability - if something goes wrong, one company is responsible
• Programme certainty - the contractor manages the sequencing of trades
• Lower time commitment for you - typically half a day per week on site visits and administration
• Easier to get a mortgage - lenders find main contractor projects straightforward to manage
• Cleaner Build Regulations process - one contractor, one set of signed-off documents

Cons

• Higher cost - typically 15-25% more than direct labour for the same output
• Less visibility of what is being paid for what
• Less control over specification if the contractor substitutes materials

Best for

Self-builders with full-time jobs who cannot commit significant time to site management, those without construction industry experience, and those building in areas where labour is scarce and coordinating trades independently would be very difficult.

Route 2: Package company

A package company (also called a kit home supplier or system build company) provides the structural system for your home - typically a timber frame, SIP panel, or ICF system - and manages its delivery and erection. You manage all subsequent trades yourself: groundworks, first fix, plastering, second fix, and fit-out.

Well-known UK package companies include Potton, Scandia-Hus, Baufritz, Fleming Homes, and Kingspan Timber Solutions. Each has a different product range, price point, and level of support.

Pros

• Structural risk is largely removed - the package company designs and builds the shell to a known specification
• Programme certainty for the shell - factory manufacture means the frame goes up quickly once on site
• Energy performance is predictable - factory-built systems can achieve very high insulation values consistently
• Some package companies offer project management support for the post-shell phase

Cons

• You still manage all trades after the shell is up - the coordination burden shifts rather than disappears
• Package companies tie you to their structural system - changing course is expensive
• Can be more expensive than a site-built alternative for the structural element
• Quality of post-sale support varies significantly between companies

Best for

Self-builders who want predictability and quality on the structural envelope but are comfortable managing trades for fit-out. Particularly good for those targeting high energy performance, as factory-built systems are easier to detail correctly than site-built alternatives.

Route 3: Direct labour

You act as the project manager, appointing and coordinating all trades directly and buying materials yourself. There is no main contractor. You deal with groundworkers, bricklayers or frame erectors, roofers, plumbers, electricians, plasterers, carpenters, and decorators separately - coordinating their programmes, managing payments, resolving problems, and taking responsibility for quality at every stage.

Pros

• Potentially 20-35% lower cost than a main contractor route for the same specification
• Complete visibility of what everything costs
• Full control over specification, materials, and quality standards
• Ability to do some tasks yourself if you have relevant skills (painting, landscaping, tiling)

Cons

• Very significant time commitment - typically two to four days per week, sometimes more
• You carry all coordination risk - a gap between trades causes delay and cost
• You are responsible for health and safety compliance as the principal designer and contractor
• Finding and retaining good trades independently is hard in areas with low unemployment
• Some self-build mortgage lenders are cautious about direct labour projects
• Disputes with individual trades must be managed by you with no main contractor to fall back on

Best for

Self-builders with construction industry experience or project management skills, those with flexibility in their working pattern to be on site regularly, and those for whom maximising cost savings is the primary objective.

Comparison at a glance

Hybrid approaches

Many self-builders use a hybrid approach - for example, appointing a package company for the structural shell and then using direct labour for all subsequent trades. Or using a main contractor for groundworks and structure, then switching to direct labour for first and second fix. There is no rule that says you must use one route throughout the entire project.

The key is to be clear about where the responsibility boundaries lie at each transition point, and to document them in your build contract.