How HalloSara's AI Property Valuation Works
HalloSara produces a free property valuation in less than two minutes through four steps: enter your address and location, specify the property type and size, describe the year of construction and condition, then immediately read the AI-generated report. The algorithmic estimate combines current standard land values (Bodenrichtwerte), regional market data, and a condition factor; Claude AI by Anthropic then analyses the property in greater depth and delivers an individually formulated assessment with context.
Step 1: Enter Your Address
The address is the single most important factor in property valuation — according to an analysis by ImmoScout24 market report Q1 2026, location accounts for up to 60 percent of price variation between comparable properties. HalloSara uses the address to retrieve the current standard land value (Bodenrichtwert) and regional price level.
Standard land values (Bodenrichtwerte) are published annually or biennially by the local valuation committees (Gutachterausschuesse) of each federal state and represent the official benchmark for land value per square metre. HalloSara accesses an up-to-date database of these values and combines them with regional transaction data from property listing platforms to calculate a market baseline for the entered address. The more precise the address — including the house number — the more accurate the location assessment.
Step 2: Property Type and Size
Whether a property is an apartment (Eigentumswohnung), a single-family house (Einfamilienhaus), a multi-family building (Mehrfamilienhaus), or a building plot (Grundstueck) significantly affects its value, because different buyer groups, valuation methods, and market prices apply to each type. Floor area in square metres is the most important scaling factor.
HalloSara distinguishes between apartments (valued using the comparative method with an apartment type factor), single-family and semi-detached houses (combining asset and comparative methods), and multi-family buildings (income capitalisation method). The stated floor area is multiplied by the price per square metre for the property type in its specific location. Building plots are assessed using the standard land value and plot size, with an additional floor area ratio premium applied to development land.
Step 3: Year of Construction and Condition
The year of construction determines the theoretical remaining useful life of a property and therefore the age-related depreciation; the condition adjusts this depreciation up or down depending on whether the property has been modernised or requires renovation. Together these two factors account for 20 to 35 percent of value variation among properties with comparable location and size, according to the Federal Statistical Office (Destatis) 2024.
HalloSara uses a simplified condition scale from very good to poor to determine a condition factor between 0.7 and 1.2. Very good (fully refurbished, modernised) corresponds to a factor of 1.1 to 1.2; good condition sits at 1.0 as the baseline; in need of renovation reduces to 0.8 to 0.85; poor condition to 0.7. A complete modernisation of heating, bathroom, facade, and windows can extend the remaining useful life by 20 to 30 years, significantly increasing the asset value.
Step 4: Receive Your AI Analysis
After the fourth step, HalloSara immediately displays the algorithmically determined value range and simultaneously initiates an individual analysis by Claude AI from Anthropic, which places the property in deeper context and formulates strengths, risks, and recommendations.
The algorithmic value range is derived from the land value, the building's asset or income value, and the applied market adjustment factor. Claude AI reads all entered data, combines it with broad market knowledge, and produces an assessment tailored specifically to the property — including typical buyer arguments for this property type, regional market trends, and concrete action recommendations. The complete report can be downloaded as a PDF and serves as a basis for discussions with estate agents or prospective buyers. What distinguishes HalloSara from other tools is the combination of algorithmic precision and AI-generated explanatory text: the result is not just a number but an understanding of that value.
Frequently Asked Questions
Is the valuation really free?
Yes, the complete valuation including the algorithmic value range and Claude AI analysis is free of charge. There are no hidden costs. HalloSara generates revenue through referral fees when property owners choose to engage an agent from our network — this is entirely voluntary and never pressured.
How accurate is the AI valuation?
For well-comparable properties in German cities, the algorithmic estimate typically achieves a deviation of 5 to 15 percent from the actual market price. The Claude AI analysis is a qualitative assessment rather than a numerical valuation. For legally binding purposes, a certified expert appraisal is required; HalloSara is designed for initial orientation and decision preparation.
Is my data stored?
HalloSara stores valuation requests in a secure database in order to send you the report by email and enable future comparisons. Personal contact details are only stored if you voluntarily provide them in the contact form. All data is stored on European servers and processed in accordance with GDPR. Full details are available in the privacy policy.
Can I download the valuation as a PDF?
Yes, after completing your valuation you can download the full report as a PDF. The PDF includes the value range, all entered property data, the Claude AI analysis, a market context section, and a summary of the key value drivers and risks.