Predictika · Building product quotes

An AI sales agent's roof window quote, checked before it goes out

An AI sales agent prepares a quote for roof windows: the window type, finish, glazing and size, the flashing for the roofing, optional blinds and profile sets, and a total. Before it goes out, the agent sends it to Predictika, which checks it against a declarative model of the published catalogue rules and prices and returns a verdict, every reason, a line-item quote and the figures it computed.

Scope: single roof window quotes from the VELUX UK 2026 catalogue: window prices by type, finish, glazing and size, flashing fit by roofing material and pitch, profile set, solar blind and a total excluding VAT. See everything this validator covers

This validator models single roof window quotes built on the prices and notes in the VELUX UK Product Catalogue 2026 (UK price list valid from 1 July 2026), not just the scenarios shown below.

  • Window prices — manual, solar and electric centre-pivot, and manual and electric top-hung, in maintenance-free and painted finishes with the listed glazings and sizes, added into a line-item quote with the flashing, an optional solar Anti-heat blind (MSL 5060) and an optional ZWP profile set, and compared with the total the agent states.
  • Flashing fit — each single flashing (EDW, EDL, EDP, EDT, EDN, EDJ) is checked against the roofing material, its thickness or profile height, the tile length for plain tiles and the roof pitch range of the flashing and of the window.
  • Installation notes — electric top-hung windows with recessed flashing need the ZWP profile set, windows side by side in one opening need a combination flashing, and a manual top-hung window at a roof pitch above 55 degrees needs special springs, which goes to a person.

Any single roof window quote that touches these rules is in scope — not only the scenarios pictured here. Not covered: combination flashings, dormer and flat roof windows, the solar integrator and other blinds, replacement flashings, the Pro 1000 variants, the Heritage and Conservation windows, sizes without a listed price (including FK08 and UK08), discounts, installation labour and VAT. Assumptions: every single flashing is allowed with every single window type, prices are whole pounds excluding VAT, and a combination the catalogue does not price is blocked as unpriced, not as unavailable.

The AI sales agentBuilds the roof window quote from the conversation and says it is ready.
Predictika validatorChecks every rule at once and returns the verdict, each finding, and the computed figures.

7 scenarios in 3 groups · each group runs from the agent’s first attempt to the outcome · click one to switch

What the agent proposes

The AI sales agent says

Illustrative agent statement. The validator receives the structured request below.

Proposing agent: AI sales agent (scripted)

Before sending, the agent must call Recorded run

Predictika validator


      

        
        
        
      

      
Waiting for the call.

      
    

  

  
  

    
Where rules-based CPQ gets it wrong
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Our assessment of what a typical rules-based CPQ (product rules, price rules and validation rules, as in Salesforce CPQ) does with the same cases. It is a judgment about effort and reliability, not a claim that nothing can be built.

    
What the validator caughtTypical rules-based CPQPredictika
Prices that depend on the type, finish, glazing and sizeOnly with care
A price book with a row per variant and size. It works, but the book is large and every catalogue change is another set of rows to keep in step.		The prices are looked up from the choices and every line is totaled together.
Stated totals that must equal what the catalogue givesOnly with care
A stated figure is a free-entry field; a rule can compare it with a computed total, but the total has to follow the flashing, blind and profile set on every line.		The stated total travels with the quote and is compared with the computed total on every call.
A flashing that suits the roofing material, thickness and pitchOnly with care
A compatibility rule per flashing, material and thickness limit. It works, but the limits are many and easy to leave out.		The flashing is checked against the roofing material, its thickness, the tile length and the pitch ranges together.
A required add-on that depends on the window and flashingOnly with workarounds
The profile set is needed only for an electric top-hung window with a recessed flashing, so it is a rule across two lines that interacts with the others.		The window type, flashing and profile set are in one request and are checked with the rest.
Every problem returned in one answerOnly with workarounds
Rules tend to fire as the quote is saved or a step is completed, so a rep often fixes one error and meets the next.		All findings come back together, whatever order the choices arrived in.

  

  

    
What this validator catches: findings from its test cases
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Every rule is checked on every call, in any order the choices arrive; one problem never hides another. Blocking findings stop the quote; approval findings need a person to sign off; everything else is computed.

    
1The quote states a total of 659 pounds; the catalogue prices give 658 pounds.
2The chosen window type, finish, glazing and size have no price in the VELUX UK 2026 catalogue price tables, so this validator cannot price it.
3The electric top-hung roof window needs the ZWP profile set for recessed installation (EDN and EDJ flashings); it is not on the quote.
4The ZWP profile set is listed in the catalogue only for electric top-hung roof windows.
5A roof pitch of 12 degrees is outside the range of the chosen window (centre-pivot 15 to 90 degrees, manual top-hung 15 to 75 degrees, electric top-hung 15 to 65 degrees).
6A roof pitch of 12 degrees is outside the range of the chosen flashing (EDW and EDL 15 to 90 degrees; EDP 25 to 90 degrees; EDT, EDN and EDJ 20 to 90 degrees).
7A manual top-hung roof window is standard for roof pitches of 15 to 55 degrees; at 60 degrees it needs special springs, which must be specified when ordering, so a person should confirm.
8The EDW flashing is for profiled roofing material, interlocking slate, thatch and profiled sheeting; it is not for the roofing material on the quote.
9The EDL flashing is for slate up to 8 mm thick and is not for interlocking slate; it is not for the roofing material on the quote.
10The EDW flashing takes profiled roofing material up to 120 mm in profile; the roofing on the quote is 121 mm.
11The EDJ recessed flashing takes roofing up to 90 mm in profile; the roofing on the quote is 91 mm.
12The EDL and EDN flashings take slate up to 8 mm thick; the slate on the quote is 9 mm.
13The EDP flashing takes plain tiles up to 14 mm thick; the tiles on the quote are 15 mm.
14The EDP flashing takes plain tiles up to 300 mm long; the tiles on the quote are 310 mm long.
15The EDT flashing takes flat tiles 15 to 40 mm thick; the tiles on the quote are 14 mm.
16The EDT flashing is for flat tiles; it is not for the roofing material on the quote.
17Windows installed side by side in one opening need a VELUX combination flashing; the single flashings on the quote do not join windows, and combination flashings are not covered by this validator.
18The catalogue lists no price for the solar Anti-heat blind MSL 5060 in the chosen window size.
19The quote has 0 roof windows; at least 1 is needed.

  

  

    
Scenarios and results
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The recorded result of the validator for each scenario on this page: the request the AI agent sent, the verdict, and every finding, in the order they appear above.

    
1. Flashing and stated total: Slate roof, four windows with solar blinds, and a flashing made for another roofing material

    
The agent's request. Please quote 4 manual centre-pivot roof windows, maintenance-free finish, glazing 0066, size PK08, each with an EDW flashing, for a slate roof at a pitch of 38 degrees, with roofing 8 mm thick, and a solar Anti-heat blind (MSL 5060) on each window. The quote states a total of £5,504 excluding VAT. It is ready to send.

    
Verdict: Blocked.

    
    
      
  • Flashing does not suit the roofing. The EDW flashing is for profiled roofing material, interlocking slate, thatch and profiled sheeting; it is not for the roofing material on the quote.
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  • Stated total does not match. The quote states a total of £5,504; the catalogue prices give £6,100.
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2. Flashing and stated total: The agent resubmits after fixing the errors

    
The agent's request. Please quote 4 manual centre-pivot roof windows, maintenance-free finish, glazing 0066, size PK08, each with an EDL flashing, for a slate roof at a pitch of 38 degrees, with roofing 8 mm thick, and a solar Anti-heat blind (MSL 5060) on each window. The quote states a total of £6,100 excluding VAT. It is ready to send.

    
Verdict: Allowed.

    
    
      
  • Order summary. 4 window(s) at £1,032 each, flashing at £149 each and a solar Anti-heat blind at £344 each; unit total £1,525, order total £6,100 excluding VAT.
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3. Recessed installation: Electric top-hung windows with recessed flashing and no profile set

    
The agent's request. Please quote 3 electric top-hung roof windows, maintenance-free finish, glazing 0066, size MK06, each with an EDN flashing, for a slate roof at a pitch of 40 degrees, with roofing 8 mm thick. The quote states a total of £5,043 excluding VAT. It is ready to send.

    
Verdict: Blocked.

    
    
      
  • Profile set missing. The electric top-hung roof window needs the ZWP profile set for recessed installation (EDN and EDJ flashings); it is not on the quote.
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4. Recessed installation: The agent resubmits after fixing the errors

    
The agent's request. Please quote 3 electric top-hung roof windows, maintenance-free finish, glazing 0066, size MK06, each with an EDN flashing, for a slate roof at a pitch of 40 degrees, with roofing 8 mm thick, and a ZWP profile set on each window. The quote states a total of £5,214 excluding VAT. It is ready to send.

    
Verdict: Allowed.

    
    
      
  • Order summary. 3 window(s) at £1,481 each, flashing at £200 each and a ZWP profile set at £57 each; unit total £1,738, order total £5,214 excluding VAT.
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5. Steep roof and special springs: Steep plain-tile roof with the wrong flashing, a stated total that is too low and a top-hung window

    
The agent's request. Please quote 3 manual top-hung roof windows, painted finish, glazing 0068, size MK08, each with an EDT flashing, for a plain tile roof at a pitch of 62 degrees, with roofing 14 mm thick and tiles 265 mm long. The quote states a total of £2,871 excluding VAT. It is ready to send.

    
Verdict: Blocked.

    
    
      
  • Flashing does not suit the roofing. The EDT flashing is for flat tiles; it is not for the roofing material on the quote.
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  • Stated total does not match. The quote states a total of £2,871; the catalogue prices give £3,036.
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  • Special springs to confirm. A manual top-hung roof window is standard for roof pitches of 15 to 55 degrees; at 62 degrees it needs special springs, which must be specified when ordering, so a person should confirm.
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6. Steep roof and special springs: The agent resubmits after fixing the errors

    
The agent's request. Please quote 3 manual top-hung roof windows, painted finish, glazing 0068, size MK08, each with an EDP flashing, for a plain tile roof at a pitch of 62 degrees, with roofing 14 mm thick and tiles 265 mm long. The quote states a total of £2,871 excluding VAT. It is ready to send.

    
Verdict: Needs approval.

    
    
      
  • Special springs to confirm. A manual top-hung roof window is standard for roof pitches of 15 to 55 degrees; at 62 degrees it needs special springs, which must be specified when ordering, so a person should confirm.
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  • Order summary. 3 window(s) at £824 each plus flashing at £133 each; unit total £957, order total £2,871 excluding VAT.
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7. Steep roof and special springs: The agent resubmits after fixing the errors

    
The agent's request. Please quote 3 manual centre-pivot roof windows, painted finish, glazing 0068, size MK08, each with an EDP flashing, for a plain tile roof at a pitch of 62 degrees, with roofing 14 mm thick and tiles 265 mm long. The quote states a total of £2,286 excluding VAT. It is ready to send.

    
Verdict: Allowed.

    
    
      
  • Order summary. 3 window(s) at £629 each plus flashing at £133 each; unit total £762, order total £2,286 excluding VAT.
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Narration transcript
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The text of the narrated walkthrough, step by step.

    
    
      
  1. Welcome to a demo of Predictika's Validator. An AI sales agent prepares a quote for roof windows: the window type, finish, glazing and size, and more. Before it goes out, the agent sends it to Predictika, which checks it against a declarative model of the published catalogue rules and prices and returns a verdict, every reason, a line-item quote and the figures it computed.
    2. 
      
  2. I will start with the first request by the agent.
    3. 
      
  3. The agent says. Please quote 3 manual top-hung roof windows, painted finish, glazing 0068, size MK08, each with an EDT flashing, for a plain tile roof at a pitch of 62 degrees. The quote states a total of £2,871 excluding VAT. The rest of the request is on screen.
    4. 
      
  4. Before it goes out, the agent calls the validator.
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  5. Blocked, with two findings and one approval, all in one answer. The EDT flashing is for flat tiles; it is not for the roofing material on the quote. The quote states a total of £2,871; the catalogue prices give £3,036.
    6. 
      
  6. The validator returned two blocking findings and one approval in one answer. A check that reads one field at a time would pass most of this; it shows only when the choices in the quote are checked against each other and against the stated total.
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  7. What this shows: for a flashing that suits the roofing material, thickness and pitch, a rules-based CPQ is error-prone for this.
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  8. Now the agent resubmits.
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  9. The corrected request. It changes the flashing to EDP.
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  10. It calls the validator again.
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  11. Not blocked, but held for a person.
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  12. The validator also returns the line-item quote, on screen.
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  13. The two blocking findings are cleared; one approval remains for a person: special springs to confirm.
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  14. The agent resubmits once more.
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  15. The revised request. It changes the opening type to manual centre-pivot and the stated total, excluding VAT to £2,286.
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  16. It calls the validator once more.
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  17. This time the validator clears it.
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  18. The validator also returns the line-item quote, on screen.
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  19. The earlier finding is cleared, and the validator's total, £2,286, matches the quote.
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  20. Three problems caught in one call, fixed in two passes, and a clean £2,286 quote. That is the value of Predictika's validator: catching mistakes before they reach the customer. Now you can try the other scenarios yourself.
    21.