Executive Summary
The current lease extension premium is assessed on a live-input basis.
Lease Extension Valuation
Lease Extension Dashboard - Advanced Analysis
What kind of ground rent structure do you have?
Potential Reform Console
Live policy scenarios
Bespoke reform settings
These are custom scenario assumptions you can toggle individually instead of using the full package.
Inputs
Years remaining on lease:
years
months
Ground Rent (£ per year):
per annum
Property Value (if extended)?
Capitalisation rates by range:
Deferment Rate % (advanced users only):
Years remaining on lease:
years
months
Current Ground Rent (£ per year):
per annum
Standard Capitalisation Rate (%):
RPI Growth Rate (%):
Rent Review Frequency (years):
Years Until Next Review:
Equivalent Capitalisation Rate (%):
Property Value (if extended)?
Deferment Rate % (advanced users only):
Years remaining on lease:
years
months
Current Fixed Ground Rent:
Standard Capitalisation Rate (%):
Rent Review Frequency (years):
Years Until Next Review:
Property Value (if extended)?
Deferment Rate % (advanced users only):
Expected Premium
-
Low
Reform£
Current law£
-
Medium
Reform£
Current law£
-
High
Reform£
Current law£
Composition Mix
Urgency Gauge
Driven by years remaining and the 80-year threshold
Flexible window
More than 90 years remaining keeps the timing pressure lower.
Years Left
0.0
Distance To 80
0.0 years
Premium Curve
Cost Of Waiting
Baseline drift assumes 4% HPI each yearScenario Matrix
8-Year Forecast
Prepared Analysis
Valuation Working Report
Live model output
Fixed Ground Rent scenario
Premium Composition
The premium is apportioned between compensation for lost rent, the reversionary interest and any marriage value where applicable.
Timing Commentary
Timing sensitivity is determined by years remaining on the lease and any proximity to the 80-year threshold.
Applied Assumptions
- Rent Model
- Fixed Ground Rent
- Years Remaining
- 0.0 years
- Property Value
- £0
- Ground Rent
- £0 pa
- Capitalisation
- 0.00%
- Deferment
- 0.00%
Professional Opinion
On the live assumptions applied, the premium can be read as a reasoned working estimate for planning and negotiation review.
Working Calculations Schedule
Line-by-line build-up of the premium in the style of a formal working paper. Click any line to expand the formula, meaning and landlord-loss rationale.
Current live calculation
| Line Item | Working Basis | Amount |
|---|---|---|
| Working calculations will populate from the live dashboard inputs. | ||
Method Notes
- Scenario-specific working notes will populate from the live dashboard inputs.
Formula Glossary
- GR-1
- Ground rent compensation calculation reference.
Mathematical Appendix
Formal Valuation Formulae
Symbolic expressions only
Rent Stream Capitalisation
Lr = G0 · SUMt∈T ( 1 + y )-t
Lr,idx = SUMk∈K Gk · INTTkTk+1 ( 1 + y )-t dt
Gk = G0 · PRODj<k ( 1 + ij )pj
Reversion And Deferment
R0 = VL · ( 1 + d )-T
R90 = VL · ( 1 + d )-( T + E )
Pv = R0 - R90
Relativity And Marriage Value
VS = VL · f( T, a, b )
M = s · [ VL + R90 - VS - Lr - R0 ]+
s = s( T ) , [x]+ = max( x , 0 )
Total Premium Operator
P = Lr + Pv + M
PL = P( y + dy , aL )
PM = P( y , aM )
PH = P( y - dy , aH )
Scenario Matrix And Delay Surface
P( h , n ) = P[ T - n , G0 , VL · ( 1 + h )n , y , d ]
D( n ) = P( h* , n ) - P( h* , 0 )
S = { P( hr , nc ) }r,c , r ∈ R , c ∈ N
Functional Form
F : ( T , G , V , y , d , i , p , w ) → P
dP = ( dP / dT ) dT + ( dP / dG ) dG + ( dP / dV ) dV + ( dP / dy ) dy + ( dP / dd ) dd
HP = [ d2P / dxi dxj ]