Understanding the Impact of the Building Safety Act on Your Project: A Comprehensive Guide
- MWArchitectural
- Apr 16
- 6 min read
Updated: Apr 17
Whether you're planning to build a new home, extend your current property, or convert a building into residential units, understanding your legal responsibilities is essential—especially when it comes to safety. One of the most important recent changes in UK construction law is the Building Safety Act 2022. While much of the conversation around this Act has focused on high-rise towers, it also has implications for smaller residential projects, including those carried out by self-builders, homeowners and small developers. Even if your project doesn’t fall under the stricter “higher-risk” category, we’ll explain when the Act applies, what your duties are as a client, and how the key roles of Principal Designer and Principal Contractor help you meet those duties.
What is the Building Safety Act?
The Building Safety Act 2022 was introduced in response to the Grenfell Tower tragedy, with the goal of improving building safety and accountability across the industry. It introduces stronger oversight through the new Building Safety Regulator, and defines clear roles and responsibilities throughout a building’s lifecycle—from design and construction to occupation and maintenance.
Although the Act places the most stringent controls on Higher-Risk Buildings (HRBs)—which are residential buildings over 18 metres or 7 storeys high with at least two residential units—it also reinforces existing responsibilities on all building projects, regardless of size and that includes home extensions, refurbishments, loft conversions, and smaller residential developments. In short, even smaller-scale projects are expected to follow good practice around safety, risk management, and record keeping.
Does It Apply to My Project?
If your project is a single-family home, extension, or a small-scale residential development (e.g. converting a property into flats), it's likely not classified as a Higher-Risk Building. However, the Building Safety Act applies to all works that require Building Regulations approval and also reinforces and enhances existing rules under the Construction (Design and Management) Regulations 2015 (CDM 2015)—rules that apply to all construction work, no matter the scale.
This means as the client commissioning the work, the Act creates new legal responsibilities, even if your project is relatively small.
Your Duties as a Residential Client
As a homeowner or small-scale developer, your primary duty is to make suitable arrangements for managing health and safety during the project. This doesn’t mean you need to become an expert in construction law—but you do need to appoint the right people to help manage safety on your behalf.
Your main responsibilities include:
1. Allocating enough resource (time and money)
Crucially, a client must allow enough time and money for both the design and construction phases to enable those involved in the work to meet building regulations. Although perhaps obvious, constraining the ability of designers and contractors to carry out their duties with lower fees or unrealistic timescales tilts any responsibility for non-compliance towards the client. This doesn't mean a designer or contractor can wholly claim zero responsibility but a client must understand that in order to protect the integrity of the design there are particular services, products or advice that must be procured to achieve successful compliance and the responsibility for bearing the cost of this rests with the client.
2. Appointing Competent People
You must appoint a Principal Designer (for the design phase). It is frequent for the design phase to run parallel with the build phase as products and technical details change i.e. a Principal Designer's obligations typically do not end when construction begins. You must also appoint a Principal Contractor (for the build phase) if more than one contractor will be involved on your project. These appointments must be made in writing. For many residential clients, your architect typically takes on the Principal Designer role and this is automatic in the case of small-scale domestic projects. They need to be able to demonstrate that they are competent, qualified and have the organisational capacity to take on the work: their involvement goes beyond just 'supplying drawings' and takes on a holistic, collaborative position that is responsible for the overarching compliance during any matters of design.
3. Providing Pre-Construction Information
You need to share any relevant information you have about the site—for example, if it’s on a slope, near utilities, or has existing hazards (like asbestos or structural concerns). Your team will use this to design and plan the work safely. A lot of this should rightly be picked up as part of your designer's or contractor's site assessment but there might be identifiable hazards that are not obvious such as ground contamination, concealed gas pipes or electrical wiring, hidden voids or unstable structures above. There is scope for demonstrating that some hazards are unforeseen but you need to make sure that you have taken 'reasonable' steps to ensure that all foreseeable aspects that could impact building regulations compliance have been explored.
4. Maintaining Oversight (Light-Touch for Domestic Clients)
If you’re acting in a purely domestic capacity (e.g. a private homeowner extending your house), the legal responsibility to carry out your duties is usually transferred to the Principal Designer and Principal Contractor. However, if you're a developer or landlord, these responsibilities stay with you and must be managed proactively.
5. Understanding the Golden Thread (For Larger or Multi-Unit Developments)
If your project involves multiple residential units or you’re developing a property that could fall into the higher-risk category now or in future, it's important to begin maintaining accurate digital records of design decisions, materials, and safety information. This is known as the ‘Golden Thread’, and while it's not mandatory for most small projects, it's a good practice that’s becoming increasingly expected. This practically means accurate, digital copies of drawings, specifications, change logs, inspection or approval correspondence,
The Role of the Principal Designer
The Principal Designer manages Building Regulations compliance and health and safety during the design phase (again, it's worth mentioning here that the design phase typically runs throughout the build of the project right up until handover or even after it if there are defects to put right). Typically, your architectural designer will take on this role.
It's important to recognise that here we are talking about the Building Regulations Principal Designer (BR PD) which is a separate - albeit linked - role to the Construction Design and Management Principal Designer (CDM PD), both of which fall under different legislation. It is possible to fulfill one function and not the other although the government's intent with the purposeful (and arguably confusing) similar naming choice is to encourage the two roles being filled by one party. In theory this will give a joined-up approach to how a building's design will comply with all relevant regulations and a single point of contact for responsibility.
Their duties include:
The principal designer is responsible for overseeing the design phase of a project, including planning, managing, and monitoring all design activities, ensuring that the design work is progressing according to schedule and that all relevant parties are involved in the design process (i.e. engineers, specialist consultants etc).
Identifying and eliminating design risks (e.g. considering safe access for maintenance).
Advising you on your responsibilities
Helping to gather and pass on relevant health and safety information for the construction phase
Signing a declaration at the point of Building Regulations approval (typically after completion) stating the design complies
Even on small projects, this ensures that your design choices meet your aesthetic and functional ambitions but also long-term safety.
The Role of the Principal Contractor
The Principal Contractor is responsible for health and safety on-site during construction. They’ll:
Plan and manage the build with safety in mind
Coordinate all subcontractors and trades
Ensure workers are trained and working safely
Record works to prove regulatory compliance and provide you with information at the end of the project, including maintenance instructions and any safety-critical features
If your builder is managing other trades (like electricians, plumbers, etc.), they will usually act as the Principal Contractor. Your responsibility is to make sure they understand their role and are competent to fulfil it.
In Summary
The Building Safety Act is about creating safer, better-managed buildings—regardless of size. For most residential clients, the implications are manageable with the right professional support. By appointing a qualified Principal Designer and Principal Contractor, sharing relevant information, and maintaining oversight where needed, you’ll not only meet your legal duties but help ensure your project is delivered safely and responsibly.
If you’re planning a new home, extension, or small development, or just want to learn more about what to expect from a Principal Designer, get in touch.
