Technical SEO refers to the optimisation of a website's infrastructure — server configuration, code quality, crawlability, and indexability — to help search engines access, crawl, interpret, and index your content effectively. It is distinct from on-page SEO (content optimisation) and off-page SEO (link building).
For AEC firms, key technical SEO issues include: missing or misconfigured sitemap.xml and robots.txt files, slow page load speeds (especially on image-heavy portfolio pages), broken internal links, redirect chains, non-secure HTTP pages, and missing canonical tags that create duplicate content problems.
Mobile-first indexing means Google primarily uses the mobile version of your site for ranking. A firm website that looks great on desktop but has a broken mobile layout can see significant ranking drops as a result.
HTTPS is now a baseline ranking signal. All AEC firm websites should serve content over HTTPS with a valid SSL certificate. Beyond security, it also builds trust with prospective clients who may be evaluating your firm for significant projects.