The digital sustainability playbook

This playbook brings together UK marketing, compliance, and development teams around digital sustainability. It shows each team what they own, why they should care, and how to collaborate to reduce website carbon footprints, implement green hosting, and build sustainable web practices that deliver environmental and business wins.

You'll find:

• Insights and results from real B2B projects
• A cross-team digital sustainability checklist

But what about:

• Return on investment?
• Lead generation? 
• Cheaper infrastructure costs?
• Better website performance? 
• Avoiding compliance mishaps?
• Better SEO performance?
• Employee advocacy and client retention?
• Making the planet better for the next generation? 

Sustainable websites are the invisible thread that helps achieve your key goals. 

Do you know your website's impact? 

Wherever you stand personally, making environmental change happen at an organisational level is a different challenge; influencing the board can be tricky when governance, budgets, and competing business priorities are involved. 

Everyone approaches environmental issues at a different pace; you might have a mix of people at your company who:

1. Care about the environment but don't realise how much carbon websites produce.
2. Feel frustrated that their company isn't taking digital sustainability seriously.
3. Don't want to prioritise low-carbon website development (yet).

All states of mind are understandable, but we can't ignore digital sustainability. It's long been one of the C-suite's top emerging priorities. Sustainability is a key KPI that companies will evaluate going forward. Partners, suppliers, and investors are all looking at sustainability reports like they used to look at earnings reports - Deloitte.

A digitally sustainable site minimises environmental impact while maximising business value. 

• Sustainable cloud infrastructure - Efficient code and architecture that cuts server costs
• Green hosting - Renewable-powered data centres for ESG compliance
• Carbon-smart caching - Strategic content delivery that reduces load
• Sustainable UX - Lightweight, fast pages that boost SEO and conversions

Every sustainable choice you make for your website solves a business problem you already have. Lower costs, better performance and happier users.

Understanding the regulatory landscape for digital sustainability helps UK businesses prepare for current and future website carbon footprint reporting requirements.

The EU 

For some UK businesses, the EU's CSRD (Corporate Sustainability Reporting Directive) affects business:

If your company has subsidiaries in the EU, earns €150M+ revenue in the EU or is listed on the EU stock markets, you'll need to file sustainability reports to the EU.

These companies may also report under the Scope 3 regulation (which may include digital services). However, reporting digital services is notoriously tricky as digital solutions can consist of lots of "parts," including purchased services (like hosting) and sold products (when customers visit your website, their device energy consumption can be considered). 

Website carbon calculators can offer a practical starting point. While they can't measure every variable, these tools use industry-standard methodologies to give you baselines and kick-start valuable improvements. 

Comprehensive reporting is required for companies in this category, and you'll likely combine website carbon calculator estimates with hosting provider carbon reports, CDN sustainability data, and spend-based calculations for gaps.

The UK Government 

Most UK companies are still in the early stages of understanding their website's digital carbon footprint, let alone reporting it. 

Even large companies in the UK only need to report on Scope 3 voluntarily. 

But things are changing (slowly). Groups like the Green Web Foundation and BIMA's sustainability council are fighting for much more transparency and responsible reporting on our digital carbon footprint, and this conversation will likely extend to more formal UK standards sometime soon.

Why do these regulations matter? 

It's not just official bodies looking at our websites; it's a global conversation getting louder.

We're seeing steady interest in low-carbon website development across the tech industry. 

Search trends show consistent growth, and for a good reason:

• AI and cloud computing are raising awareness of digital energy use and website carbon footprint

• Procurement teams increasingly ask about green hosting and sustainable infrastructure

• Website carbon calculators and measurement tools are improving rapidly

• Digital service providers are educating users that performance and low-carbon design go hand-in-hand

Remember how accessibility and mobile optimisation moved from "nice-to-have" to expected best practices? Sustainable web development follows the same path. 

Understanding digital sustainability now means you're prepared—whether for future regulation, stakeholder demands, or simply building faster, more efficient websites through sustainable UX and green infrastructure.

Three digital experts—spanning marketing, QA, and development—share what happens when sustainability is ignored in a digital project and how future-ready teams are tackling it to drive measurable results.

If you had asked me a few months ago about website builds or hosting, I would have passed you straight to the development team. 

That was until I realised the link between sustainable websites, performance, and lead generation.

Here are six reasons why ignoring digital sustainability can cost you: 

1. Sub-par SEO: 

Google considers technical performance just as important as content quality. If your pages are slow to load, unstable as they render, or sluggish to interact with, they'll be marked down in rankings, no matter how good the copy.

How do you know if your website's performance might hold back your SEO?

I like to check core web vitals, a set of speed and user experience metrics in tools like Google Search Console, Screaming Frog, or Sitebulb. If your pages fail against benchmarks, you're likely losing organic visibility, especially on mobile.

Ignoring this metric might make you think your SEO isn't working (despite your A* content and meticulous media library efforts) when the culprit could be your website infrastructure. 

2. Lost conversions

Reliability fosters trust in the B2B website industry. 

Slow-loading pages, laggy customer portals and clunky downloads can instantly erode a potential lead's trust (especially when highly confidential data is involved). 

Page-load time is one of the most significant factors determining whether users stay or leave.

According to a recent article from the Search Engine Journal, users are far more likely to bounce if a page takes longer than 2.5 seconds to load. 

So, provided your website's content and media library implementations are on point, chat with your development team if your pages load faster than 2.5 seconds. 

3. Clients slipping away

For B2B firms, platforms don't just showcase services — they deliver legal updates, financial reports, project milestones, and everything in between. 

Even if your service is excellent, a site that feels unreliable gives the impression that something might be broken elsewhere, too.

Sustainable websites perform flawlessly simply because they're built with leaner code and lighter pages. This reduces downtime and improves how portals, dashboards, and download areas work. This helps your valued clients stick around and reduces the need for awkward " Is your portal down?" emails.

4. Employee advocacy flops

Advocacy programmes are everywhere, and the move to shouting about your B2B firm on platforms like LinkedIn, Facebook and Instagram is huge. 

Still, as many marketers will understand, employee advocacy cannot be forced. 

To naturally encourage employee social sharing, you can create a hub of environmental content that aligns with your workforce's values. This is especially relevant for B2B brands with multi-generational teams. 

Gen Z has consistently ranked climate change and social responsibility among their top concerns (Deloitte Global Millennial and Gen Z Survey, 2024). 

Giving your team something to share that they believe in (like green issues) can result in better content, thought leadership, and social reach for your B2B business.

5. Creeping cost-per-lead

A slow website can quietly waste your marketing budget.

Let's say you've paid for ad clicks and invested time in organic content and email campaigns, but users bounce before acting on your campaign. It seems obvious that a sluggish website increases the bounce rate, scares away leads, and inflates your cost-per-lead, even with all the great content and work you've put in. 

It's a frustrating reality that often results from overlooking the sustainability and performance of your website infrastructure.

6. Carbon content strategy

I love this one. Sustainable websites give marketers and content strategists a new branch of content to explore: carbon content.

From a recent digital project, our client, Russell-Cooke, added their Green Web Foundation credentials to their website following the sustainable hosting overhaul. Small actions like this open the door to content opportunities, including green case studies, sustainability commitment updates and brand innovation stories that users love.

77% of UK consumers trust sustainability claims with official certifications" (Zero Carbon Academy). So, official green certifications are content gold for content marketers' teams. 

They open up a new pillar of storytelling and are an easy way to demonstrate thought leadership on a topic that will only become more relevant. 

When I test for speed, efficiency, and website bloat, I assess the same elements that impact your environmental footprint and business performance! What do I spot that contributes the most to digital waste and lost conversions? 

Here are the five main things:

1. Uncompressed images

Slow-loading hero images tank SEO, burn energy, and quietly kill conversions.

One of the most common issues is huge images that haven't been optimised. Designers export a nice-looking banner, but no one checks the file size—it goes live at 3MB or more.

Large images are often the #1 reason pages are "heavy." Images typically account for 70–80% of a web page's total size. 

This can turn a 2-second load into 5. And that matters—half of mobile users leave if a site takes more than three seconds to load. That one bloated image could cost you half your potential leads.

Aside from slowing down pages, serving oversized images has a sustainability cost. All those extra bytes travelling over the network and being rendered on-screen consume electricity on servers, networks, and user devices.

2. Autoplay videos

Autoplay often causes users to bounce or stall, hurting lead flow, especially on mobile.

Video is powerful—but not when it plays without being asked.

One report estimates that a 30-second HD video clip can easily add ~10 MB to a page's payload. I've seen this myself: a 2 MB page with just an image becomes 12 MB with autoplay video. That's a 4–5× jump in data that can quadruple the slow connections' load time.

From a sustainability point of view, autoplay burns bandwidth and energy for content people didn't even choose to watch, especially mobile users.

3. Lazy loading errors

Lazy-loading mistakes damage brand perception and kill conversions. 88% of online consumers are less likely to return to a site after a bad experience, and broken images and clunky loading count as bad experiences, right? My job is to catch them before your users do.

What is lazy loading?

Lazy loading is meant to help pages load faster by holding off on loading things until needed. But when it breaks, it's a disaster.

Even small mistakes can delay key visuals or throw off the layout. Hidden media also creates a carbon problem: it still uses energy to load, even when no one sees it.

4. Unused third-party scripts

Unused scripts quietly cost you leads, slow your site, and waste your marketing budget.

Running any old tracking scripts, abandoned pop-ups, or A/B test tags still running in the background?

They're easy to forget, but they load on every page, slowing things down for no good reason. Your users don't need them; sometimes, teams don't even know they're still there. 

Today's average webpage loads more than 35 third-party scripts, often the most significant contributor to JavaScript bloat. It's like trying to run a race with a backpack full of bricks. Every unnecessary script adds weight, eats carbon, and chips away at your website's performance.

5. Bloated JavaScript bundles with dead code

Your site's JavaScript—the code that powers buttons, menus, and pop-ups—is meant to help the user. But often, it includes features no one uses.

I often test sites with a main JavaScript file that is over 2MB. That's a lot for one page. Even if the user doesn't need it, their device must still download, process, and run the whole thing.

That takes time, especially on older phones. A few seconds of delay might not seem like much, but Amazon found that even 100 milliseconds of added load time cost them 1% in sales.

1. Sustainable cloud infrastructure 

Sustainable cloud infrastructure can save brands up to 85% in bills and carbon emissions!

If you're not familiar with the term, sustainable cloud infrastructure is just about running your website in a way that uses fewer resources when you don't need them.

Most websites today run 24/7 — including staging, test, and development environments that might not be touched for days. If left unchecked, this leads to:

- High cloud bills
- Unnecessary energy usage
- Extra emissions that fly under the radar

It's like leaving the lights, heating, and monitors on in every building room — whether anyone's in or not.

Sustainable cloud infrastructure in action

This is where Azure container apps come in. My team and I have used Azure Container Apps to build systems that act like motion-sensor lighting:

- When someone visits the site, it works.
- When things go quiet, it scales down.

My team recently moved a leading UK charity to a more modern infrastructure: Azure Container Apps. 

Here's what the green cloud infrastructure transformation achieved:

1. Reduced monthly hosting costs by 85%
2. Cut carbon emissions by approximately 85%
3. Improved site performance, despite using a fraction of the computing resources 

The charity now saves over £5,000 annually - money redirected to its mission - while its website runs faster and more reliably than before. This setup works brilliantly for organisations with variable traffic patterns. 

Azure Container Apps only consume resources when needed, which means this charity's presence now has the carbon footprint of a small household rather than a small office building.

It's a perfect example of how modern cloud infrastructure can be dramatically more affordable, perform better, and be more environmentally responsible.

2. Green hosting and carbon-smart caching 

Green hosting and carbon-smart caching reduce cost and emissions. 

Once your cloud infrastructure is more intelligent and scales responsibly, the next step is to ensure it runs on cleaner power and performs as well as possible. 

That's where green hosting and carbon-smart caching come in. Now, I've mentioned three sustainable development methods:

- Sustainable cloud infrastructure: HOW your systems run (Azure Container Apps - like motion-sensor lights for websites)

- Green hosting: WHERE they run (Good providers powered by wind, solar, or other green energy)

- Carbon-smart caching: HOW content reaches users (Storing popular content nearby so it loads faster with less energy)

With all three implemented, your website will work smarter. Instead of running 24/7, it scales down when quiet, uses clean energy, and uses carbon-smart caching to serve popular pages without extra energy (and cash).

Green hosting and carbon-smart caching in action

In a recent B2B website project, our professional services client saw the following after implementing a green host and carbon-smart caching. 

1. - 35% reduction in server load, meaning their current hosting could handle 35% more traffic
2. 35% reduction in carbon emissions
3. Potential for 35% cost savings

The best results come from combining all three: sustainable cloud infrastructure, green hosting and carbon-smart caching. 

When you do that, you reduce costs and make real, measurable carbon reductions that matter to your brand.

No matter what team you're on, there are simple, high-impact sustainability changes you can make to support your department's goals—and help your website run cleaner, faster, and greener.

• Marketing teams are improving SEO, lead gen, and user trust
• Developers are reducing infrastructure cost and complexity
• Compliance teams getting ahead of regulation

You now have the insights to bring your team into the sustainable web era. Whether in marketing, compliance, or development, this topic is for everyone. 

Want to find out where your website stands and how to make it greener, faster, and cheaper?

Check your free digital sustainability score using our advanced Website Carbon Calculator, or ask our friendly team about Digital Sustainability Consulting.