Level 3 Survey & Valuation for RTB

I need a comprehensive Level 3 Structural Building Survey and a retrospective market valuation for a Right to Buy (RTB) application.

Requirements:
- Level 3 survey: Detailed inspection of a flat suffering from subsidence
- Retrospective market valuation: Reflects the application submission date.
- Purpose: Support my RTB application.

Ideal skills and experience:
- RICS accredited surveyor
- Experience with Level 3 surveys
- Knowledge of market valuations for RTB purposes
- Attention to detail and accuracy

I require a fixed-fee quote for an independent Building Survey (Level 3) combined with a Retrospective Market Valuation for a 1-bedroom second-floor flat within a Victorian terraced conversion on Tufnell Park Road, London, N7.
The building is suffering from severe, active foundation movement/subsidence. This report and valuation is required to support a formal statutory review of a District Valuer's determination under the Right to Buy scheme (Section 128 of the Housing Act 1985).
The instruction has highly specific parameters that must be met within the final report:
1. Retrospective Valuation Date: In accordance with Section 127 of the Housing Act 1985, the property must be valued at the statutory "relevant time" of 19th November 2024. The valuation must reflect the market reality and asset condition on that exact date.
2. Active Structural Subsidence: The building is suffering from severe, active foundation movement/subsidence. The District Valuer has formally logged “evidence of structural movement within the flat and common areas, with structural gapping between the building structure and timber-framed windows/doors.” Internal partition doors and windows are warped out of square. The ceiling of the flat directly below (Flat B) has previously suffered a structural cave-in.
3. Specific Valuation Focus: The report must provide a definitive RICS Red Book valuation that explicitly accounts for:
o The capital cost of building-wide underpinning/stabilisation.
o The property's absolute lack of traditional mortgageability due to active, un-remedied block subsidence.
o The required "cash-buyer discount" and the extreme difficulty or un-insurability of the building fabric.
4. EPC Thermal Backlog: The property holds an EPC rating of D, with a documented £17,000 cost backlog to remedy uninsulated solid walls (£11k) and rotten single-glazed joinery (£6k).
I am currently awaiting the formal issuance of a Revised Section 125 Notice from Islington Council, which will trigger a strict 28-day statutory window to submit my appeal.
Could you please provide:
• Your fixed fee for a combined Level 3 Structural Survey and Retrospective Red Book Valuation.
• Your current lead time for an inspection once instructed.
• Your standard turnaround time for delivering the final PDF report post-inspection.