Hidden Building Costs That Catch Most People Out

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Importance of Project Planning

Give me six hours to chop down a tree, and I will spend the first four sharpening the axe. - Abraham Lincoln

It is the same with project planning and executing a building project; there is a temptation and aspiration to act quickly and rush through the early RIBA Stages, but in reality, these stages are the most critical to avoid hidden project costs that will crop up during the construction stage.

Digital Twin Modelling

One of the most overlooked ways to reduce cost is investing early in digital twin modelling.

A digital twin is a detailed, data-rich replica of your future building, created on the computer before construction begins. Unlike standard 3D models, these include every construction detail, material specification, and site variable, often drawn from point-cloud surveys and topographical mapping.

Why does this matter?

Because most budget overruns stem from unforeseen problems during construction:

• Misinterpreted site conditions

• Incomplete or vague drawings

• Late-stage design changes

These surprises often trigger costly change orders when it's too late to competitively reprice. A well-made digital twin prevents this. It forces clarity early, revealing issues before they become expensive. It’s especially useful when working in tricky sites, like Green Belt plots or sloping terrain, where context matters.

While some clients initially question the upfront cost, it consistently pays for itself. In our practice, digital twin models have saved clients thousands of pounds by preventing delays, abortive work, and rushed site decisions.

3D digital twin model of the Monocoque Cabin showing its curved structural frame, bracing, and labelled components used for precision construction.

Right-Sizing the Design

“We saved £14,000 in contractor fees just by using a digital twin.”

One of the most effective ways to reduce project costs is to reassess the scale of the design before construction begins. All too often, projects are larger than they need to be and, unsurprisingly, these projects end up running over budget. It’s not uncommon to see developments where certain rooms or extensions remain unused as that excess space is simply not needed costly redundancies rather than assets.

This is where a skilled architect can deliver real value, often saving far more than their fee might suggest. Thoughtful space planning and design restraint are powerful tools. Clever strategies such as built-in furniture, multi-purpose rooms, or integrated furniture can optimise space, improve usability, and reduce material waste.

These small, intentional design moves add up quickly. When combined, they can significantly reduce build costs while maintaining, and often improving, the quality, comfort, and character of the final building.

Passive Design: How to Cut Energy Costs Using Natural Ventilation

“In 8 out of 10 projects, passive ventilation reduces the mechanical system cost by over 27%.”

One of the most effective and underutilised ways to reduce building costs is by making use of nature in the design. This involves making the site work in harmony with the architecture itself.

Take ventilation, for example. Most modern buildings rely heavily on mechanical systems: fans, air conditioning, and heat pumps, which are costly to install and expensive to run. But with passive ventilation, the building uses air movement, window placement, thermal mass, and orientation to regulate its temperature. Since April this year, I have been having conversations with clients who are concerned about the risks of overheating in their future home. You can click this link to read more about preventing overheating in your home.

Passive ventilation is based on vernacular architecture from Mediterranean courtyard homes to Scottish crofts. Today, these vernacular practices are unfortunately being overlooked. When done properly, passive design can significantly reduce or even eliminate the need for mechanical systems.

A well-oriented, well-ventilated eco-home can often run comfortably on solar alone — saving thousands both upfront and over its lifetime. Even without renewables, passive strategies lower energy use, simplify installation, and reduce maintenance.

Rather than adding technology to fix design problems, passive architecture prevents them at the source, creating buildings that are efficient, resilient, and connected to their surroundings.

A sun path diagram showing building orientation in relation to the sun’s movement across the day and seasons. This analysis helps optimise natural light, reduce overheating, and improve energy efficiency through passive design.

Building on Sloping Sites Without Blowing the Budget

Every site has its own character: slopes, trees, and natural contours, yet too often these are flattened in the pursuit of a “perfect” foundation. Heavy excavation and poured concrete rarely make sense; they’re costly, disruptive, and unnecessary for most builds.

A better approach is to work with the land. By following the site’s natural fall or gently lifting the structure above it, you can minimise groundworks and create a building that feels rooted in its setting.

One of the most effective foundation systems for uneven or sensitive sites is the ground screw (or screw pile). These steel supports are wound directly into the soil, providing stability with minimal disturbance. They eliminate the need for excavation, reduce environmental impact, and are particularly suited to timber or modular construction.

Unlike concrete, ground screws preserve existing vegetation and tree roots, making them more acceptable to planning officers and ecologists alike. They’re fast to install, easy to remove if required, and offer a low-impact, cost-effective solution for sloping or protected landscapes.

Ground screws installed on a sloping green field, providing a stable and level foundation frame for a future structure. This low-impact solution avoids heavy excavation, preserving the natural landscape and reducing build costs.

Conclusion

In our opinion, the most effective way to save money on a project is through thorough and intentional planning. This means developing a deep understanding of the site, its unique context, and the surrounding environment. By working in harmony with the natural topography, incorporating sustainable materials, and leveraging the environment for strategies like passive ventilation, you can create a design that is cost-effective, efficient, and environmentally sensitive.

Effective planning ensures that every aspect of the project, whether it’s foundation methods, energy systems, or design interventions, is tailored to the specifics of the site. This not only reduces costs but also delivers a project that is seamlessly integrated with its environment, creating long-term value for both the client and the planet.