A cheaper product can lower the tender total and increase the cost of owning the building.
It can also be the right choice. The task is to establish which is which before accepting the substitution.
For property developers, useful value engineering starts with the function each element must perform. That gives the team a basis for simplifying the design while protecting the requirements that matter.
Name the requirement before comparing products
Write down what the element needs to achieve. Depending on its location and purpose, that may involve durability, fire performance, weather resistance, acoustic performance or accessibility.
Some requirements are regulatory. Others come from the client's brief, planning conditions or the intended use of the property. Treat those as constraints in the review rather than optional extras.
Then compare products and construction methods that meet the relevant requirements. A broadly similar appearance does not establish technical equivalence.
Compare the installed assembly
The item on the supplier's quotation may be only part of the cost.
Check supporting work, fixings, preparation, specialist labour and interfaces with adjacent construction. A less expensive finish may need a different substrate. A changed component may require new detailing or affect another trade's work.
Ask the contractor to show the net saving, including associated changes. Confirm the effect on programme and availability rather than assuming a product change is cost-neutral elsewhere.
Keep the technical designer involved. The saving should survive coordination with the rest of the building.
Look for simpler construction
Some of the most useful cost reviews examine how the design is assembled.
Repeated dimensions, coordinated service routes and fewer bespoke junctions may reduce complexity where they suit the project. These are options to price, not automatic savings to promise.
For example, rationalising window sizes may make procurement simpler, but the decision still needs to respect the elevations, room layout and required performance. The design should be reviewed as a whole.
Consider maintenance and replacement
Ask how the element will be inspected, cleaned, repaired and eventually replaced.
For a rental development, access for maintenance and the availability of replacement components can matter throughout ownership. For a development intended for sale, durability and clear operating information still affect the building delivered to the buyer.
A whole-life comparison should state the assessment period and assumptions. Predicted service lives, maintenance intervals and future prices are estimates, not promises.
Use specialist cost advice where a significant decision depends on those calculations.
Record the agreed specification
Once an alternative is approved, update the drawings and specification and confirm who is responsible for procurement and installation. Retain the evidence used to assess its suitability.
A substitution described only as “equivalent” leaves too much unresolved. Define the actual product or performance requirement and the relevant installation details.
Contact Horizon Architecture to discuss a technical design review that gives your cost adviser and contractor a clearer basis for assessing value.
