How do you get your house built?

The influx of house-building programmes on TV has done wonders for the number of people wanting to commission their own home, but the actual means by which they get them built still remains a mystery for many. As architects specialising in private homes, we appreciate that the procurement process can seem daunting to first-time self-builders – even the language surrounding it can leave people scratching their heads. We’ve created a guide below to outline the standard options for building private homes.

Procurement is the means by which the construction of a project is sourced, or ‘bought’ (i.e. from whom the clients buy construction services). There are many different ways to procure a project, depending on the type of building and client; for houses we typically consider two procurement routes: a Traditional Contract or a Construction Management route.

Tendering a project involves inviting contractors or sub-contractors to submit an offer for the supply of their services or goods. In the case of house-building, this could be for the overall build of the entire house, or specific packages of work. We typically ‘Tender’ a project once we have compiled a complete set of technical drawings, enabling all parties to establish the extent and quality of work required.

Traditional Contract is the most common method of construction procurement. The contractor provides a fixed price based on the Tender documents; these documents consist of detailed construction information about the project (primarily created by us, but also involving information from the structural engineers, M+E engineers, and any other design team consultants). The contractors use this information to cost the scheme, so it is important that it is detailed, complete and accurate. On top of the net build costs, the contractor will charge a percentage to cover their own company overheads and profits. Unless there are changes to the scheme, or specific events, the client will not pay any more or less than the Tender sum for the project - regardless of how much it actually costs the contractor to carry out the works.

The contractor has a contract directly with the client and deals with all sub-contractors. This gives the clients a simple single point of contractual responsibility for the construction. We are involved to administer the contract, and are responsible for certifying requests for payment, assessing delays or financial penalties. Essentially, we are an impartial umpire, there to referee between the client and contractor. Once the building is completed, we continue to administer the contract to oversee the rectification period (typically 6 or 12 months post-completion). This means that any defects that occur during this period are identified by us and put right by the contractor.

PROS

• cost certainty
• low risk to client
• set completion date
• contractor penalties for late completion
• simple contractual relationship
• architect acts as contract administrator to ease pressure on client
• ‘safety net’ of the rectification period provides peace of mind for resolving defects at no cost to the client

CONS

• additional costs for contractor’s overheads and profits
• more difficult and expensive to make changes after Tender
• less client involvement during construction
• can be considered as more adversarial, “them and us”

Construction Management means that the project will be built by various sub-contractors who have individual, direct contracts with the client. These trades are managed and supervised by a single Construction Manager, who deals with obtaining individual tenders, liaising with sub-contractors, programming, sequencing of trades, and site co-ordination. The Construction Manager will ordinarily charge a management fee for their involvement, rather than the sums charged by main contractors under Traditional Procurement (i.e. company overheads and profits).

Our role is different compared to that under Traditional Procurement, although we will still maintain a relationship, visit site, highlight deviations from the construction package, and work with the construction manager to find more cost-effective solutions. There is no main building contract for us to administer, and we do not assess or certify invoices. We are still involved with site issues and queries, and if the client wants late changes to be made. This option does not have the cost certainty of a lump-sum Traditional Contract. In most cases the project manager’s fees are much lower than a main contractor’s overheads and profit. It may also be less expensive to make late changes with this procurement route, but it does not have the same contractual obligations or mechanisms as a Traditional route (ie financial penalties or defect rectification).

PROS

• potentially lower build costs
• easier to make late changes or adapt specification
• potential for more client involvement and control
• more collaborative experience

CONS

• no cost certainty
• no contract administrator to impartially assess works, invoices, delays etc
• no architect’s site inspections to maintain standards
• no contractual obligation for trades to carry-out rectification works (any involvement of the construction manager would incur additional fee)