Why TrustMark Registration Matters
Under PAS2035:2019, retrofit assessment and design must be carried out by a qualified professional. TrustMark registration is the recognised UK quality standard for retrofit assessors, ensuring they have undergone rigorous vetting and meet strict competency requirements. Selecting a registered assessor protects your project, reduces risk, and ensures compliance with building regulations and energy efficiency standards.
Understanding TrustMark Retrofit Assessor Credentials
TrustMark-registered retrofit assessors must hold specific qualifications and maintain ongoing professional development. The registration scheme requires assessors to demonstrate:
- Relevant building science and retrofit knowledge
- Understanding of PAS2035 and PAS2030 standards
- Technical competency in surveying and assessment methodologies
- Professional indemnity insurance
- Commitment to continuing professional development
Assessors are registered under the PAS 2035 Retrofit Assessor scheme and must renew their credentials periodically, ensuring current expertise and compliance with evolving standards.
How to Verify TrustMark Registration
Before engaging an assessor, always verify their status through the official channels:
- Visit the TrustMark website and use the Find a Tradesperson search tool
- Search by postcode or company name to locate registered assessors in your area
- Check the assessor's registration number and confirmation of scope
- Verify the registration is current and has not expired
- Confirm their specific retrofit assessment credentials
A legitimate TrustMark assessor will have a unique registration number and their entry should display their accreditation date and scope of work. If an assessor cannot provide verifiable registration details, do not proceed.
Key point: Always independently verify registration through TrustMark's official search tool. Do not rely solely on company claims or website statements about registration status.
Assessing Assessor Experience and Expertise
Beyond TrustMark registration, consider the assessor's practical experience with retrofit projects:
Relevant Experience
- Years working in retrofit assessment and building surveying
- Portfolio of completed PAS2035 retrofit projects
- Experience with your specific building type (e.g. terraced housing, flats, listed buildings)
- Familiarity with local authority requirements and building control procedures
Technical Specialism
- Understanding of thermal imaging and heat loss diagnosis
- Knowledge of moisture and ventilation risks in retrofits
- Experience with different retrofit measures (insulation, heat pumps, windows, renewables)
- Ability to design solutions for hard-to-treat properties
Professional Standing
- Membership of relevant professional bodies (RIBA, CIBSE, IES, or similar)
- Track record of professional conduct and customer satisfaction
- Transparent fee structure and project timescales
- Evidence of professional indemnity insurance
Questions to Ask Potential Assessors
When contacting assessors, ask specific questions to evaluate their suitability:
- Can you confirm your current TrustMark registration number and scope?
- How many PAS2035 retrofit assessments have you completed?
- What is your experience with [your building type]?
- How do you approach survey methodology and risk identification?
- What is your typical timescale for completion?
- How do you manage communication and reporting?
- Can you provide references from recent projects?
- What is your fee structure and what does it include?
Comparing Quotations and Scope
Retrofit assessment costs vary based on property size, complexity, and location. When comparing quotations:
- Ensure all quotes cover the full PAS2035 assessment scope
- Check whether thermal imaging is included
- Confirm the assessment includes a written Retrofit Design Specification
- Verify whether site visits cover all relevant building areas
- Clarify fees for report revisions or additional queries
- Understand timescales for survey, analysis, and reporting
The cheapest quote is not necessarily the best. An experienced assessor may take longer to produce a thorough, risk-aware specification that prevents costly problems later.
Red Flags to Avoid
Be cautious of assessors who:
- Cannot provide verifiable TrustMark registration details
- Offer generic reports without site-specific analysis
- Recommend the same retrofit measures for different property types
- Lack professional indemnity insurance
- Cannot discuss PAS2035 and PAS2030 compliance in detail
- Refuse to explain their methodology or answer technical questions
- Pressure you into decisions without proper survey data
Making Your Final Selection
Your choice of assessor shapes the entire retrofit project. A high-quality assessment provides confidence in recommended measures, supports smooth building control approval, and reduces risk of problems during and after work. Invest time in selecting an assessor with proven credentials, relevant experience, and clear communication skills. The assessment cost is typically 1–2% of overall retrofit investment, making quality assessment excellent value.
Once appointed, ensure the assessor has clear project requirements, building access for thorough surveying, and sufficient time to deliver a comprehensive specification that reflects your property's specific needs.