Construction · service #1 · class C

AI construction estimate generator for Spain

From the project documentation or a defect report — to the work items and quantities, the resource breakdown and a by-chapter estimate with correct VAT and PEM/PEC formulas in your own Excel template. AI prepares the draft; a person reviews and approves it.

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~10 min by-chapter estimate · instead of 1–2 h [estimate]
10/21% VAT without mix-ups · art. 91 LIVA rules; doubtful cases go to a person
PEM→PEC GG 13% + BI 6% formulas · computed by Excel, not the model
BC3 export to Presto / Arquímedes · FIEBDC-3 · to confirm

Where the hours and margin leak away

01 · Problem
market estimate (buildgets.com, 2026) [V]
1–2 h

per typical estimate, by hand

Measurements from a notebook, rates from old estimates, formulas by hand. Complex jobs: 4 to 40 hours.

art. 91 LIVA; AEAT, 2026
+11 p.p.

the cost of a VAT error

The 10% rate for home renovation requires three conditions at once (private client, dwelling ≥ 2 years old, materials ≤ 40% of the base). Get it wrong — reassessment at 21%.

medicionpro.com, 2026 [V]
80–120

items rekeyed by hand

When the project or estimate arrives as a PDF, items and quantities are copied into the software by hand: 3–5 hours per typical job, with errors.

And while the estimate is being built, the lead goes cold: a slow reply reads as a no.

Estimating is a production process

02 · The process we close
source documents (project · defect report · site visit) work items & quantities (mediciones) resource breakdown (descompuestos) presupuesto by chapters certificaciones de obra
CLASS

Class C · production. An estimate is a unit of output with a flow and a bottleneck, so the effect is measured in throughput, time and errors. Secondary class — A: a fast estimate keeps the deal from going cold. The bottleneck is almost always the first two links: getting the work items and quantities out of the documents and breaking them down into resources.

Today — by hand

Items and quantities are rekeyed by hand from the project PDF, the defect report is turned into work items «from experience», resource breakdowns come from old estimates, formulas and VAT — by hand. Hours of concentration, and still errors and forgotten items.

With the system

Provide the project or the defect report — get a draft: work items and quantities, a resource breakdown built on the price base, and a by-chapter estimate with PEM→GG→BI→PEC formulas and the correct VAT in your own Excel template. All that is left is to check the quantities and approve.

Input → AI → output. And where the person is

03 · How it works

An estimate does not come out of thin air — it needs source material. So the work starts with the documents: the AI extracts the work items and quantities from them, builds the resource breakdown and only then calculates the estimate.

Input

Source documents

  • The project (proyecto de ejecución): memoria, drawings, estado de mediciones — even as a PDF
  • Or a defect report: ITE/IEE, informe de patologías — the list of defects to fix
  • Or the site-visit take-off (renovation without a project) + your Excel template and chapters
AI

What the AI does

  • Parses the documentation: extracts work items and quantities (partidas + mediciones) from the project PDF; turns report defects into work items
  • Builds the resource breakdown: splits each item into labour, materials and machinery (descompuestos) using the price base and its output rates
  • Assembles the by-chapter estimate: PEM → +GG 13% → +BI 6% = PEC formulas, VAT 10/21% under art. 91 LIVA
Output

What you get

  • The estimate in your Excel: quantities → resource breakdown → PEM → PEC
  • Every figure is traceable: the quantity to the document, the price to the price base
  • An «indicative until site visit» note; BC3 (FIEBDC-3) export for Presto / Arquímedes — on the Pro plan, «to confirm»
Human

What the person does

  • Checks the extracted quantities against the drawings and the report
  • Reviews prices and tolerances, approves before sending — «on approval» level
  • The signature and the responsibility stay with your técnico
RULE 01

Arithmetic is done by Excel formulas, not by the language model: numeric AI errors in tables are documented, so the sums are computed by code.

RULE 02

Prices come only from the price base. The AI proposes candidates and shows where each figure comes from — it does not invent rates.

RULE 03

Quantities extracted from documents are traceable to their source. Anything measured «off the drawing» without an estado de mediciones is a draft: a person confirms the take-off.

RULE 04

Any low-confidence item is flagged «review». No silent substitutions.

What is included — and what is not

04 · What is included
Included
  • Parsing of source documents (PDF): project / estado de mediciones / defect report → a draft of work items and quantities
  • Resource breakdown: items split into labour, materials and machinery (descompuestos) using the price base
  • Claude for Excel set up on your corporate template
  • A custom Skill with your chapters: demoliciones, albañilería, fontanería, electricidad, carpintería, pintura, revestimientos, gestión RCD
  • A starter price base from open sources, adapted to your rates
  • Automatic PEM → +13% → +6% = PEC formulas and VAT 10/21% classification
  • A how-to protocol + recorded walkthrough + short consultation — the product explains itself
  • An «indicative until site visit» note in every estimate file
Not included
  • Precise take-off from drawings: AI object counts and dimensions from photos/PDFs are approximate — measurements remain yours
  • Final rates without review, or «auto-sending» to the client
  • CTE/LOE project checks and the técnico's signature — that is always a person
  • VBA/macros and Data Tables — a Claude for Excel limitation
Integrations & data
Excel — nativeBC3 · FIEBDC-3 — export · to confirmPresto — BC3 import · to confirmArquímedes (CYPE) — BC3 import · to confirmCYPE · BEDEC · PREOC — with your subscription

Commercial price banks (CYPE, ITeC's BEDEC, PREOC) are connected only under your active subscription — the data rights stay on your side. The starter base uses open sources: Andalusia's BCCA (free, BC3 format) and the open DDC-CWICR catalogue (CC-BY-4.0, includes a Spanish section).

Five steps — launch in as little as 10 days

05 · Implementation
01

Audit

0.5 days · Your template, chapters and rates. We measure the baseline: what an estimate costs you today.

02

Setup

2–4 days · A Skill with your chapters + template + price base tailored to you.

03

Test

3–5 jobs · A run against your past estimates: PEM/PEC/VAT checked down to zero discrepancies.

04

Launch

from 10 days after start · Guide + recorded walkthrough + short consultation — your team works without us.

05

Support

by subscription · SLA-backed support, quarterly rate updates, chapter fine-tuning.

SLA: Reply ≤ 1 business day (Pro — ≤ 4 h) · If it does not fit the window, the scope is too wide: we cut the scope, not the quality.

The economics, counted conservatively

06 · Economic effect

An ROI canvas for a small construction company: 12 estimates a month. Every assumption is explicit — recalculated with your data during the audit.

ParameterValueSource / assumption
Process and classestimate production — class C (secondary A)litcore framework, block 2
Volume12 estimates/month[estimate] — refined during the audit
Time «before»~2 h per typical estimate[estimate]; complex — 4–40 h (market, 2026 [V])
Time «after»~20 min: input + human review[estimate] — fixed by measuring the pilot
Estimator's rate~€35/h[estimate] — we use your real one
Time lever12 × 1.7 h × €35 ≈ €700/monthcalculation, at adoption plateau
VAT and arithmetic errorsfewer reassessments and reworksreserve — not in the conservative scenario
Reply speed to the clientfewer leads gone coldreserve — not in the conservative scenario
CostsStart from €690 + €39/mo«from» price — approved by the owner
PAYBACK

≈ 2 months. Start at €690 with 12 estimates/month and a €35/h rate, on a 40/70/100% adoption curve over 3 months [estimate]. Conservatively — within the quarter; only the time lever is counted, the reserves come on top.

Adoption: every new estimate goes through the generatorEfficiency: minutes per estimate before/after, hours per monthQuality: PEM/PEC/VAT discrepancies vs the manual estimate — zero in the testSatisfaction: the team works from the guide, without us

Not financial advice: the calculation is a proposal built on market reference points; final figures are fixed after the audit and a pilot on your data.

Want this calculated on your numbers? Request a proposal →

Price — from €690

07 · Price

Model: one-off setup (done-for-you) + a support subscription with rate updates. The range depends on your template and chapter set — the final price is fixed after the audit.

Start
from 690 €

+ €39/mo — support and updates

  • one template
  • basic chapters
Request a proposal →
Pro
from 1,490 €

+ €79/mo — rate updates, priority support

  • full chapter set
  • Spanish price base
  • rate updates
  • priority
Request a proposal →
A medida (Núcleo)
custom

scope and price on request

  • several crews/brands
  • CRM/bookkeeping integration
Request a proposal →

Indicative "from" prices, VAT (IVA) not included. Model: one-off setup + support subscription. The final price is approved by the owner after the audit.

THIS SERVICE IS PART OF A SYSTEM

The estimate generator is module #1 of the site-management loop (service #15, project management): your estimate becomes the cost baseline and feeds the monthly certification. It is also included in the Start «Presupuestos» (from €990) and Business «Obra bajo control» (from €3,900) bundles — one cycle, one integration, one SLA. View the management loop → View the bundles →

Risks under control

08 · Risks & control
Data

Estimates and rates are trade secrets. Only what the process needs is transferred; a DPA is signed before any real data is loaded; EU/US transfers are disclosed (EU-US DPF + SCC).

Human oversight

«On approval» level: the AI prepares the draft — a person reviews and approves it before it reaches the client. Autonomy grows only after confirmed quality.

AI Act, art. 50

From 02.08.2026 the use of AI is disclosed: estimate files carry a note that they were prepared with AI and reviewed by a person.

Professional boundary

The generator does not replace the técnico's signature, the visado or CTE/LOE checks. The estimate is indicative until the site visit; doubtful VAT goes to your asesor/gestoría.

AI-assisted — human-supervised · AI Act art. 50

09 · Custom

Not your case?

You estimate differently — in Presto, with your own chapters, with certificaciones? Describe your process — we will propose a custom solution and estimate the payback.

Describe my process

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Free demo · A person validates the result · ES / EN / RU · GDPR