For developers and commercial clients
What Is Preconstruction? The Phase That Fixes Price, Programme and Risk
Sviatoslav JerdetchiiCEO & Founder of Craftex. Updated , 6 min read
The short answer
Preconstruction is the work done before building starts: the contractor tests the design, builds the cost plan and programme, and prices the risks, so the sum you sign holds.
- It turns a design into a buildable, priced programme.
- A contractor can join after RIBA Stage 2, 3 or 4.
- It is paid for under a PCSA or NEC4 X22, or folded into a single-stage tender.
Preconstruction is the work done before building starts. The contractor tests the design, builds the cost plan and programme, and prices the risks, so the sum you sign is one that holds.
It is where most overruns are won or lost. A clash found on a drawing costs an email. The same clash found on site costs weeks, a variation and an argument about who pays.
This guide is for developers, landlords and commercial occupiers. It explains what the phase covers, when it starts, how it is contracted and when it pays for itself. Our pre-construction services start with a free review of your drawings. Want a contractor's view before you commit? Discuss your project.
What preconstruction means in construction
Preconstruction is the stage between a developed design and the first day on site. The client's design team has the scheme; the contractor now checks it can be built, in what order, for what sum and by when.
The law draws the line for you. Under the CDM Regulations 2015, the construction phase begins when construction work starts. Everything before it is pre-construction, and the client must allow sufficient time and resources for it.
In the RIBA Plan of Work 2020, this sits mostly in Stage 4, Technical Design. RIBA describes a "contractual firewall" midway through Stage 4. On a two-stage design and build project, the client may sign once the major packages are secured.
On a commercial scheme the stakes are higher than on a house. Tenants may stay in the building. Landlords, funders and building control all want answers before work starts. That is what people mean by commercial preconstruction.
What preconstruction services include
A good preconstruction phase ends with documents, not opinions. Each item below should arrive with a date and a named owner.
- Surveys and existing information. Measured, structural and services surveys, plus asbestos and utilities records. Under CDM, the client passes this pre-construction information to every contractor being considered.
- Buildability review. Builders read the drawings for sequencing, access, temporary works and tolerances between trades.
- Cost plan. The scheme priced line by line, then each estimate replaced by real package returns.
- Value engineering. Priced alternatives that keep the design intent, so you choose what to change.
- Programme. Set from supplier lead times, approvals and phasing, so the end date matches your lease or loan.
- Package tenders. Specialist packages priced in competition, with the returns shared with your cost consultant.
- Logistics and temporary works. Crane, deliveries, hoarding, propping and neighbours, agreed before mobilisation.
- Construction phase plan. CDM requires it before the construction phase begins, drawn up by the contractor or principal contractor.
The cost plan is where most clients feel the difference. Read how value engineering trims cost without cutting the design.
Our pre-construction services deliver every item on that list. The people who price your scheme are the people who build it, with about 60 % of site labour our own.
When the preconstruction phase starts
The earlier the contractor joins, the more the design can still change for free. RICS sets out the cost stages in NRM 1, and it allows contractor engagement after Stage 2, 3 or 4.
| RIBA stage | Design status | RICS cost stage | What an early contractor adds |
|---|---|---|---|
| 2 Concept Design | Massing and layout | Formal cost plan 1 | Buildability of the concept, rough sequence |
| 3 Spatial Coordination | Coordinated design | Formal cost plan 2 | Market prices, long-lead items, logistics |
| 4 Technical Design | Information to build | Formal cost plan 3 | Package tenders, programme, contract sum |
The government's Construction Playbook asks public clients to engage the supply chain in the pre-construction phase. It says this leads to more effective designs and fewer changes and cost increases downstream. Private developers get the same benefit.
Medusa in Knightsbridge reached us at RIBA Stage 2, with a concept and a few 3D visuals. Our designers priced each decision with the people who would build it. The four-floor salon and spa, 180 sq m, was built in 17 weeks.
I worked perfectly with Sviat and Joe, with their architect they came up with a very smart design for our office to fit more desks and optimise the space to its maximum capacity. They also did excellent value engineering on the MEP design proposed by others, allowing us to save around £50K. The quality and speed were outstanding we finished two weeks ahead of schedule. Highly recommend these guys.
How preconstruction is contracted and paid for
There are three common routes. The choice depends on how complete the design is and how much risk sits in it.
- Single-stage tender. Contractors price a finished design. Their preconstruction work is hidden inside the tender, and you pay for it in the price.
- Two-stage tender with a PCSA. The contractor is appointed early under a pre-construction services agreement. The building contract follows once the sum is agreed.
- NEC4 with Option X22. One contract with two stages. Stage one agrees scope, programme and prices; stage two is construction.
The JCT PCSA 2024 is written for a two-stage tender. It works with the JCT Standard Building, Design and Build, Major Project and Intermediate contracts. It can be used whether or not the contractor takes on design.
NEC4 Option X22 sits inside the Engineering and Construction Contract, Options C and E. The client states the budget at the start. That keeps the scope honest from day one.
Not sure which route fits? Compare a two-stage or single-stage tender, and decide between design and build or traditional procurement. Your employer's agent or cost consultant should check every return on your side.
Who runs preconstruction
Two teams meet in this phase. Your side brings the architect, engineers, a cost consultant or employer's agent, and the principal designer under CDM. The contractor brings a preconstruction director or manager, estimators, planners and package buyers.
At Craftex the phase is led by Martin Hickey, our Preconstruction Director, with more than 50 years in construction. He reads your drawings and tender documents first, free.
His experience shows why the phase matters. Slingsby Place in Covent Garden was led by Martin Hickey, now our Preconstruction Director, as Project Director. Before anyone started on site, there were structural surveys, a demolition sequence, a temporary works design and a logistics plan agreed with the local authority.
Health and safety duties start here too. See our guide to CDM 2015 client duties for what the client must provide and when.
When preconstruction pays for itself
Paying for preconstruction makes sense when risk is high and the design is still moving. It is rarely worth a separate fee on a small, fully designed, simple job.
- Occupied buildings. Portsoken House in Aldgate: 1,550 sq m of offices over two floors, built in 7 months while the building stayed occupied.
- Neighbours who stay. Kensington Olympia: a 400 sq m penthouse refurbished in 12 weeks, every other home in the block occupied.
- Retained façades and basements. Temporary works and sequence decide the cost.
- Higher-risk buildings. No building work may start until the Building Safety Regulator approves the application, which can take up to 12 weeks.
- Long-lead plant and façades. The programme is only as real as the supplier dates behind it.
Want a contractor's eyes on your scheme before you commit? Discuss your project. Send us the drawings and any surveys. Martin Hickey reviews cost and buildability, free and with no obligation, and we recommend a tender route.
Whichever applies, the phase should end with paper you can check. Before you sign the building contract, make sure you hold the items below.
What preconstruction should hand you before you sign
- A cost plan priced line by line, reconciled with your cost consultant
- Package tender returns for the main trades
- A programme built on supplier lead times and approvals
- A list of risks, each with its cost and owner
- Value engineering options, priced, with your decisions recorded
- A logistics plan and a construction phase plan
