Why the Cost of Materials Changes Everything in a Build
May 2026
When people think about the cost of a construction project, they often focus on the headline number: the final quote. But that number is really the result of dozens of moving parts, and one of the most influential factors is the cost of materials.
Materials don’t just determine what a building looks like. They shape how long it takes to build, how reliable the programme is, how flexible the design can be, and how well the finished space performs over time. Understanding how material costs work, and why they change, is one of the most valuable pieces of knowledge a client can have going into a build.
Materials Are the Backbone of Any Build
Every build, home extension, or refurbishment is fundamentally a collection of materials assembled in a specific order. Concrete, steel, timber, brick, insulation, plasterboard, roofing systems, finishes, each of which plays a structural or functional role.
What’s often overlooked is that materials typically account for 40–60% of the total construction cost, depending on the project type. Labour, design, preliminaries, and management make up the rest, but materials are the single largest variable. That means even small percentage changes in material pricing can have a noticeable impact on the overall budget.
Why Material Prices Change So Often
Material costs are not static, and they don’t behave like everyday consumer goods. Several external forces influence them, many of which are outside the control of contractors or clients.
1. Global Supply Chains
Most construction materials rely on international supply chains at some stage. Raw materials may be mined or harvested in one country, processed in another, and distributed from multiple hubs. Disruption anywhere along that chain such as transport delays, factory shutdowns, shipping constraints can ultimately heavily affect availability and price.
2. Energy Costs
Manufacturing materials like steel, cement, glass, and bricks is energy-intensive. When gas or electricity prices rise, production costs increase, and those costs are passed on. This is one of the biggest drivers behind recent price volatility.
3. Demand Cycles
Construction demand fluctuates. When housing activity increases or large infrastructure projects are commissioned, demand for materials rises. If supply can’t keep pace, prices follow.
4. Regulation and Compliance
Changes in building regulations, environmental standards, or sustainability requirements can alter how materials are produced or sourced. While these changes are often positive in the long term, they can temporarily increase costs.
5. Currency Movement
Many materials or components are imported. Exchange rate changes can directly affect prices, sometimes with little warning.
How Material Costs Affect Design Decisions
Material pricing doesn’t just influence the budget, it influences the design itself.
When architects and engineers are designing a project, they often make assumptions about material availability and cost. If those assumptions change later, the design may need to adapt. This can show up in several ways:
Structural systems may shift (for example, timber vs steel).
Cladding or façade materials may need to be reselected.
Internal finishes may be adjusted to stay within budget.
Buildability considerations may come forward earlier in the design process.
A design that looks great on paper but relies on volatile or long-lead materials can introduce risk. Early collaboration between designer, builder, and client helps ensure the design reflects real-world costs, not idealised ones.
Lead Times: The Hidden Cost Driver
Price is only part of the equation. Lead time is how long it takes for materials to arrive, can be just as impactful on the price outcome.
Some materials may be competitively priced but require long manufacturing or shipping periods. Others may be readily available but more expensive upfront. Delays in material delivery can cause:
Programme overruns
Extended site preliminaries
Labour downtime
Re-sequencing of works
Increased management costs
In many cases, the cheapest material on paper can become the most expensive once delays are factored in. This is why experienced contractors look at total cost impact, not just unit price.
Fixed Prices vs Reality on Site
Clients often ask why builders include allowances or contingencies for materials instead of fixed prices. The answer is risk. Quoting a build months before materials are purchased involves forecasting future prices. When markets are stable, this is relatively straightforward. When markets are volatile, locking in prices too early can expose one party to significant risk.
There are generally three approaches:
Fully Fixed Pricing - Low risk for the client, higher risk (and often higher price) from the contractor to protect against volatility.
Prime Cost or Provisional Sums - Shared risk, with flexibility to adjust once actual material costs are confirmed.
Open-Book or Cost-Plus Models - Full transparency, where the client sees actual material costs and pays accordingly.
Value Engineering: Not About Cutting Corners
When material prices rise, “value engineering” often gets mentioned. True value engineering is not about cheap substitutions. It’s about finding smarter ways to achieve the same outcome. That might include:
Using standard material sizes to reduce waste
Selecting materials with better availability
Reordering construction sequencing
Choosing systems with faster installation times
Considering lifecycle costs rather than just upfront cost
In many cases, spending slightly more on one material can reduce labour time or future maintenance costs, resulting in better overall value.
Sustainability and Material Cost
Sustainability is increasingly important, and it does influence material pricing Low-carbon materials, recycled content, and responsibly sourced products can carry higher upfront costs. However, they often deliver long-term benefits such as:
Improved energy performance
Reduced maintenance
Longer lifespan
Better compliance with planning and building standards
Increased property value
The key is understanding where sustainable materials make the biggest impact and balancing environmental goals with budget realities.
The Role of Early Procurement
One of the most effective ways to manage material cost risk is early procurement.
By identifying critical materials early, especially those with long lead times or volatile pricing, projects can:
Lock in prices sooner
Reduce exposure to market fluctuations
Protect the programme
Improve cash flow planning
Early procurement requires coordination and clear decision-making, but it can significantly reduce stress later in the build.
What Clients Can Do to Stay in Control
While clients can’t control global markets, they can control how they engage with the process. Practical steps include:
Making key material decisions early
Being open to alternative specificationsUnderstanding allowances in the contract
Asking how material risk is being managed
Prioritising performance and durability over trends
A well-informed client is far less likely to be surprised by cost changes.
At Bloom Builders London, we approach material selection and pricing with realism, transparency, and experience. By understanding how and why material costs change, clients are better equipped to make decisions that protect both their budget and their build. Construction will always involve variables. The key is knowing which ones matter most, and materials are right at the top of that list.
Sources
Costs for UK construction outstrips EU while exports fall, Uk Trade & Business Commission, https://www.tradeandbusiness.uk/news/costs-for-uk-construction-outstrips-eu-while-exports-fall?utm_.
The Impact of Fluctuating Material Costs on Global Supply Chains, CMIC Global, https://www.cmicglobal.uk/resources/article/The-Impact-of-Fluctuating-Material-Costs-on-Global-Supply-Chains?utm.
The Rising Cost of Materials: Impact on Construction Projects, FGA Architects, https://www.fga.build/article-2?utm.