PSL Engineers offer comprehensive civil and structural engineering support for construction projects across all scales, from residential renovations to large-scale commercial developments and new builds.

For homeowners seeking to expand their living space through loft conversions or extensions, we provide cost-effective, customised solutions tailored to individual needs.

Our expertise encompasses:

• Designing structural components, including beams and connections, utilising various materials.

• Creating efficient and safe structural frames and flooring systems to maximize living area.

We offer expert guidance for a range of residential projects, including:

• Loft conversions

• Rear extensions

• Load-bearing wall removal

• Other structural modifications

Our team develops innovative solutions to meet your project's specific requirements while ensuring regulatory compliance. We provide thorough structural calculations and drawings to support building control applications, in accordance with relevant design codes and standards.

By combining technical proficiency with a client-focused approach, we deliver structural design services that optimise space utilisation, enhance functionality, and ensure the long-term integrity of your property.

We are based in Liverpool - L19 and cover the north-west, including Merseyside, Wirral, North Wales, Sefton, Halton, Greater Manchester and Lancashire and Cheshire.

All our work is covered by professional indemnity insurance, with differing levels of cover depending on the nature and scale of the project.

Permitted development rights are a national grant of planning permission that allows certain construction projects and changes of use to occur without submitting a planning application. These rights originate from general planning permission granted by Parliament, not local authorities.

Types of Work Covered 

Common examples include: 

- Single-story extensions 

- Loft conversions 

- Outbuildings like sheds and garages 

- Porches 

Permitted development rights typically allow you to convert your property without planning permission if specific conditions are met, such as: 

- Volume Limits: Additional roof space must not exceed 40 cubic meters for terraced houses or 50 cubic meters for detached and semi-detached houses. 

- Materials: The conversion must use materials similar to those of the existing house. 

- Windows: Any side-facing window must be obscured glass and non-opening if it is less than 1.7 meters above the floor. 

- Height: The conversion should not extend beyond the existing roof slope at the front of the house. 

- Dormers: Any dormer windows must be set back at least 20 centimetres from the roof eaves. 

Local planning authorities can withdraw permitted development rights in certain areas by issuing an Article 4 direction, requiring planning permission for work that would usually not need it. 

Importance of Checking 

Before beginning any work, it’s essential to consult with the local planning authority to verify whether it qualifies under permitted development rights. Obtaining a Lawful Development Certificate can confirm that your proposed work is legal. 

Other Permissions 

Even if planning permission is not required under permitted development rights, other approvals, such as building regulations, may still be necessary.

Planning permission is required if.

• The house is in a conservation area, is a listed building or as had permitted development rights removed.

• A loft conversion includes a side facing window that does not meet the obscure glazing requirements

• the conversion exceeds the volume limit set out for permitted development

• The architectural plans for more complex loft conversions, such as mansard or hip-to-gable conversions, which often require planning approval.

 For loft conversions, it is generally advisable to apply for a Lawful Development Certificate, even if you think your project qualifies as permitted development. This certificate confirms that your conversion was legal when it was constructed, which can be beneficial for future property sales.

Building regulations in the United Kingdom are statutory instruments that establish minimum standards for the design, construction, and alteration of buildings. They cover various aspects of building construction and safety, including:

• Structural integrity

• Fire safety and means of escape

• Waterproofing

• Sound insulation

• Ventilation

• Electrical safety

• Accessibility

• Energy efficiency

• Process for Obtaining Building Regulations Approval

To obtain building regulations approval, follow these steps:

1. Determine Approval Needs: Check if your project requires approval (most construction and alterations do).

2. Apply: Send your application to either a local authority building control department or a registered building control approver.

3. Inspections: The building work will be inspected at various stages to ensure compliance.

Both the contractor and the building owner are responsible for meeting building regulations. Understanding this process and the roles involved can help your project proceed smoothly.

It’s crucial to check whether your project requires building regulations approval and to follow the proper procedures to ensure compliance and safety.

Ways to Get Building Regulations Approval

There are two primary methods for obtaining approval:

• Full Plans: Your architect provides detailed plans that are approved by the Building Control Officer (BCO) before any work begins.

• Building Notice: Your builder and the BCO agree on standards as the work progresses.

We facilitate this process by providing the necessary structural calculations and drawings required for these approvals.

A structural engineer is essential to ensure that the renovation works can be carried out safely and economically, on receipt of the architectural design plans we determine the type and size of structural elements (e.g., steel beams and lintels) and the necessary depth and size of foundations for your extension or conversion.

At PSL Engineers, using our wealth of experience, we ensure the necessary designs and calculations are completed in accordance with the relevant design codes and regulatory standards. The building control offices require detailed structural calculations and drawings, which we can provide efficiently and cost effectively to ensure your project meets all regulatory requirements.

Structural appraisal differs from design; its purpose is to evaluate the current condition and suitability of an existing structure.

To determine a structure's adequacy, engineering judgment is applied to information gathered from drawings, calculations, surveys, inspections, and potentially testing. Each of these activities should be conducted only to the extent necessary to reach a conclusion.

We can assist with structural appraisals and feasibility studies to assess the redevelopment potential of existing properties. We identify potential risks and provide guidance on estimated costs for any structural remediation work needed to facilitate effective renovation of a property.

When properties display structural defects, PSL Consulting Engineers can provide customised survey scopes tailored to the severity of the issue, whether it involves excessive deflection (sagging), bowing walls, structural cracking, timber rot, or subsidence. The typical survey scope includes the following.

• Specific Structural Inspection (SSI): Focuses on investigating a single structural issue, concentrating on that specific area without inspecting other rooms or areas.

• General Structural Inspection (GSI): Offers a thorough assessment of your property's condition, featuring visual inspections and reports on significant cracking and building movements. This includes evaluating the proximity of trees to determine their potential impact on foundations, reviewing soil types based on British Geological Survey records, and examining structural elements like walls, floors, load-bearing components, and openings to ensure a comprehensive evaluation of overall structural integrity.

• Comprehensive General Structural Inspection (CGSI): Includes all aspects covered in a GSI, with additional visual inspection of roof structures, cellar, outbuildings, and internal alterations.

When needed, we outline the necessary structural repair work and are available to address any questions throughout the construction process as part of our initial engagement.