Disclaimer Accuracy, Advice & Liability

Everything published on BuildMetric — including calculators, written guides, tables, diagrams, worked examples, blog posts and downloadable resources — is provided strictly as general information for the construction industry and informed property owners. It is not a design deliverable, a specification, a bill of quantities, a warranty or a certified opinion of any kind. Treat it as a well-researched reference — never as a signed-off document.

While we write for professionals, we publish for everyone. Our content does not come with any express or implied warranty of fitness for a particular purpose. We make no representation that the information is complete, current with the most recent code amendments, or applicable to your jurisdiction, occupancy classification, climate zone or site conditions. Where a calculator produces an output, that output is a mathematical result of the inputs you supplied — it is not an approval, a certificate or a professional recommendation.

Construction is a high-consequence activity. Errors in estimation, geometry, loading assumptions or material selection can lead to safety hazards, structural failure, non-compliance with building regulations, project delays, disputes with contractors, or direct financial loss. Because we have no knowledge of your specific project — the drawings, the site, the planning conditions, the warranty terms — we cannot accept responsibility for outcomes that flow from applying our content to it.

If your project involves unusual geometry, non-standard materials, heritage or conservation constraints, fire-rated assemblies, high-wind or seismic exposure, or anything that sits outside routine residential construction, treat any BuildMetric output as a preliminary reference. It is a starting point for professional scrutiny — not a final figure.

Nothing on this website constitutes professional advice of any kind. Specifically, BuildMetric does not provide — and should never be relied on for — structural engineering advice, architectural design, building control approval, quantity surveying certification, project management direction, legal advice, planning permission guidance, contract interpretation, financial modelling, insurance advice, or health and safety consultation.

These are specialist, regulated functions in every market we serve. In the United States, structural engineering work in most states requires licensure and a professional engineer's stamp. In the United Kingdom, certain work is reserved to chartered engineers, registered architects and licensed building control bodies. In Australia, design and certification are similarly regulated by state-based registration schemes. We do not hold ourselves out as offering any of these services, and no correspondence with our editorial team creates a professional-client relationship, an engagement, or a duty of care.

You should always consult an appropriately qualified professional before committing to construction where a decision involves: load-bearing elements and their modification; roof structures, truss specifications and uplift restraint; retaining walls, foundations and soil-bearing assumptions; glazing, cladding and fixings subject to wind loading; fire separation and escape routes; waterproofing and drainage; accessibility compliance; party wall, boundary and rights of light matters; or any other decision with life-safety or regulatory consequences.

Where you choose to proceed without professional advice, you do so entirely at your own risk. The responsibility for verifying suitability, compliance and constructability rests with you — or with the licensed professional you have engaged to act on your behalf.

BuildMetric calculators use published, widely accepted formulas — the same trigonometric and geometric relationships taught in engineering fundamentals. Where we reference code minimums, they are drawn from the current published edition of the relevant standard at the time of writing. We test each tool against known reference cases before publishing and re-review them periodically against new editions and errata.

Nevertheless, every calculator has inherent limitations. Our inputs assume ideal geometry, nominal dimensions and consistent material properties. In reality, sawn timber varies in actual size from its nominal size; concrete volumes assume perfect formwork; roof pitches assume straight rafters with no camber; ground conditions assume representative soil; membrane coverages assume flat, defect-free substrates. Where these assumptions do not hold — and on real sites they frequently do not — the calculator's output becomes a theoretical figure that must be adjusted on site by whoever is doing the work.

Some practical factors no online tool can fully account for:

• Waste allowances — typically 5–15% depending on the material and the complexity of cuts.
• Cutting losses on angled, hip-cut and valley members.
• Delivery minimums and packaging sizes imposed by suppliers.
• Damage in transit and site handling breakage.
• Product tolerances permitted by the relevant manufacturing standard.
• Installation overlap and lap required by the manufacturer's instructions.
• Dimensional variance between manufacturers of the same nominal product.

We present figures rounded to practical construction precision — typically two decimal places for angles, whole numbers for quantities, and consistent metric-imperial conversion. Rounding errors at that scale are negligible for estimating purposes but can accumulate across many components. For critical dimensions — setting out, structural sizing, cutting lists — always recalculate or verify with a physical measurement taken on site.

Treat every BuildMetric output as a starting estimate to be verified, cross-checked and, where necessary, adjusted by a competent professional. Do not use a calculator result as the sole basis for ordering materials, setting out on site or finalising a design.

BuildMetric serves users in the United States, the United Kingdom and Australia, and we write for all three. These markets share a common engineering language but apply different codes, different units and different approval processes. A calculator result that is correct in one market may be non-compliant in another unless the underlying standard is checked.

United States. Residential work is typically governed by the International Residential Code (IRC) or the International Building Code (IBC), but adoption is state-by-state and often city-by-city. Local amendments can be significant — seismic provisions in California, high-wind requirements in Florida, snow-load provisions in the north-east, and energy-code overlays in nearly every jurisdiction. Metric and imperial units are both used, though residential construction remains predominantly imperial.

United Kingdom. Work is governed by the Building Regulations (England & Wales), the Building (Scotland) Regulations and the Building Regulations (Northern Ireland), supported by Approved Documents and British Standards such as BS 5534 for roofing and BS 5268/BS EN 1995 for timber. The UK is fully metric, and pitch is usually expressed as an angle in degrees. Wind and rain exposure is mapped regionally, which frequently drives stricter fixing and pitch requirements in the west and north.

Australia. The National Construction Code (NCC) operates alongside Australian Standards — notably AS 1684 for timber framing and AS 4055 for wind classification — with state-based variations and additional cyclonic provisions in the far north. Metric units are universal. Compliance is typically certified by a registered building surveyor, and Bushfire Attack Level (BAL) ratings can materially affect material and detailing requirements.

Because of these differences, every BuildMetric output must be re-checked against the specific code edition, local amendment and approval pathway that applies to your site. Where a UK user specifies 30°, a US user specifies 7:12 and an Australian user specifies a 30-degree pitch to AS 1684, they are all describing roughly the same geometry — but the compliance context is not the same. We cannot and do not warrant that content written for one market is valid in another.

BuildMetric pages contain links to third-party websites — manufacturers, suppliers, standards bodies, government portals and, in some cases, affiliate partners. These links are provided for convenience and reference only. We do not control, endorse or warrant the content, products or services of any third-party site, and we are not responsible for their accuracy, availability, security or privacy practices.

Some links are affiliate links. This means BuildMetric may receive a small commission if you make a purchase after following the link, at no additional cost to you. Affiliate relationships never change the substance of our editorial content or the results our calculators produce — we do not promote products we believe to be unsuitable, and we do not adjust formulas to favour a sponsor. Any affiliate or sponsorship relationship is disclosed on the page where the link appears.

When you click an external link, you leave buildmetric.org and become subject to the destination site's terms, privacy policy and cookie practices. We recommend reviewing those before making a purchase or submitting personal data.

To the fullest extent permitted by law, BuildMetric and its contributors, editors, engineers, contractors and affiliates accept no liability for any loss, damage, injury or expense arising from the use of, or reliance on, this website, its calculators, its written content, or any linked third-party material. This includes, without limitation, direct, indirect, incidental, consequential and punitive damages; loss of profit, revenue, contract or business opportunity; cost of replacement materials or labour; cost of delay; and cost of professional remediation.

This limitation applies regardless of the legal theory advanced — contract, tort (including negligence), statutory duty, misrepresentation or otherwise — and regardless of whether we were advised of the possibility of such loss. Where the law of your jurisdiction does not permit the exclusion of certain categories of liability, our liability is limited to the maximum extent permitted by that law.

We make no warranty, express or implied, as to the uninterrupted availability of this website, the freedom of its content from error or omission, or its freedom from viruses or other harmful code. We reserve the right to modify, suspend or withdraw any part of the site at any time without notice.

If you are a consumer in the United Kingdom or the European Union, nothing in this disclaimer affects your statutory rights. If you are a consumer in Australia, nothing in this disclaimer excludes, restricts or modifies any guarantee, condition or warranty that cannot lawfully be excluded, including under the Australian Consumer Law.

All content on buildmetric.org — including written text, calculator source code, formulas, tables, diagrams, illustrations, layout and branding — is the intellectual property of BuildMetric unless otherwise credited, and is protected by copyright law in the United States, the United Kingdom, Australia and internationally.

You may view, download and print pages for your own personal, non-commercial use, and you may quote short extracts with clear attribution and a link back to the original page. You may not reproduce substantial portions of our content, mirror or scrape our calculators, republish our guides on another site, resell our data, or use our name, logo or brand assets without prior written permission.

Third-party trademarks, standards references and manufacturer specifications remain the property of their respective owners and are used for descriptive and identification purposes only.

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