Home Ownership for Families: KfW Programs 300 and 308 for New Construction and Existing Buildings

KfW 300 & 308 – for families with at least one child

Both programs are aimed at families and single parents with at least one minor child and a maximum taxable household income of 90,000 euros (plus 10,000 euros for each additional child).

Depending on the term, the interest rate advantage compared to standard market construction financing is around 2 to 3 percentage points and can amount to several tens of thousands of euros over the fixed-interest period. The application must be submitted through a primary bank or a financing broker before the start of the project or before concluding the purchase contract.

What is the KfW 300 funding “Home Ownership for Families”?

The KfW program 300 – often abbreviated as “KfW WEF 300” – is the successor to the “Baukindergeld” (child allowance for house buyers), which expired at the end of 2022. Unlike the Baukindergeld, the KfW 300 funding is not a grant, but a low-interest promotional loan from the state development bank KfW.

The interest rate reduction is financed from federal funds during the first fixed-interest period; the responsible body is the Federal Ministry for Housing, Urban Development and Building.

Funding is provided for the construction and initial acquisition of an owner-occupied, climate-friendly residential building in Germany – i.e., detached houses, semi-detached houses, terraced houses, and condominiums. In the case of an initial acquisition, the building inspection must not have taken place more than twelve months prior to the conclusion of the purchase contract.

The purchase of an existing property does not fall under KfW program 300; instead, the sister program KfW 308 has been responsible for this since September 2024, which is covered in detail further below.

Important for clarification: A repayment subsidy is not intended for the KfW loan 300. The entire funding effect is generated through the low interest rate. Anyone looking for a “KfW 300 repayment subsidy” usually confuses the program with the renovation programs of the Federal Funding for Efficient Buildings (BEG), such as loan 261.

KfW 300: Overview of Requirements

The requirements for the KfW loan 300 concern three areas: the household, the income, and the property.

Household requirements

• At the time of application, at least one child under the age of 18 must live in the household. Families as well as single parents are eligible for funding.
• The applicants must acquire at least 50 percent co-ownership of the property and use it themselves as their primary residence.
• Neither the adults in the household nor their children already own residential property in Germany – including rented out, provided free of charge, or used via usufruct.
• No funding from this program and no Baukindergeld have yet been used for the same residential unit.

KfW 300: Income Limit

The income limit for KfW 300 is 90,000 euros of taxable household income with one child. For each additional minor child in the household, the limit increases by 10,000 euros.

The decisive factor is the average of the penultimate and the year before the penultimate calendar year prior to application – for an application in 2026, this means the average of the 2023 and 2024 income tax assessments.

The crucial element is the taxable income according to § 2 EStG, not the gross income. Due to income-related expenses, special expenses, child allowances, and pension expenses, the taxable income is often significantly lower than the gross income – meaning many families with a gross income of 110,000 to 120,000 euros still meet the requirements.

Property requirements: Climate-Friendly Residential Building and QNG

The building must achieve the “Climate-Friendly Residential Building” level. Three conditions apply for this:

1. The new building reaches the Efficiency House 40 standard.
2. The requirements for greenhouse gas emissions in the building life cycle are met (life cycle assessment according to the specifications of the Sustainable Building Quality Seal – QNG).
3. The heating system does not operate on oil, gas, or biomass – in practice, this usually means a heat pump, district heating, or comparable solutions.

The higher funding level is achieved by additionally providing proof of the QNG seal in the Plus or Premium level. The combination “KfW 300 QNG” is particularly worthwhile because of the significantly higher loan amount (see next section). Details on certification are provided by the federally supported information platform qng.info.

For planning and verification, an expert from the Energy Efficiency Experts List is mandatory for both levels; they generate the “Confirmation of Application” (BzA). The costs for this specialist planning and construction supervision are among the eligible costs and can be co-financed.

There is no separate funding for energy consulting in new construction, such as BAFA offers for existing buildings – construction supervision is covered here via the loan itself.

Loan Amounts: How much loan is available under KfW program 300?

The amount of the KfW loan 300 depends on the number of minor children in the household and the funding level achieved. The status on the day of application applies – so a child who turns 18 shortly after the application is still counted.

Together with other funding resources, the loan must not exceed the total eligible costs (construction costs or purchase price including land and ancillary costs of specialist planning). In practice, the KfW 300 loan rarely covers the entire financing; the remainder is covered by a normal bank loan and equity.

KfW 300: Conditions, Interest Rate, and Repayment

The interest rate for KfW 300 is based on the capital market and is subsidized by federal funds. The interest rate trend for KfW 300 has been positive recently: In October 2025, KfW noticeably improved the conditions – an interest rate cut from around 1.7 previously to about 1.1 percent effective interest for the long term option.

For short terms, the current interest rate is sometimes significantly below 1 percent, in the best case close to the symbolic lower limit of 0.01 percent. For comparison: standard market construction financing in mid-2026 often costs 3.5 to 4.0 percent.

Note: Interest rates change constantly. Only the daily updated values in the KfW terms overview are binding. The interest rate on the day of approval applies – or the more favorable rate at the time of application receipt.

Interest rate fixed period: 20 years no longer available

From March 2024 to December 2025, KfW 300 could optionally be requested with a 20-year fixed interest rate period. KfW discontinued this option as of December 10, 2025; since then, a maximum of 10 years fixed interest rate period is possible.

For terms exceeding the fixed interest rate period, KfW will submit a prolongation offer before it expires – but then without the interest rate subsidy from federal funds. Therefore, plan the follow-up financing realistically from the very beginning and calculate the remaining debt after ten years with a higher interest rate.

Repayment and unscheduled repayment

With the annuity loan, you start with repayment-free grace years, in which only interest is due – this reduces the financial burden during the expensive construction and moving phase. Afterwards, you pay constant installments consisting of interest and principal repayment. Complete unscheduled repayment is possible against a prepayment penalty.

If you want to calculate the monthly rate and the repayment process in advance, the best KfW 300 calculator to use is the official KfW Repayment Calculator: loan amount, term, and grace years can be freely combined there – the repayment calculator works for program 300 as well as for program 308.

Example Calculation: What does KfW 300 actually provide?

Family A has two children and an average taxable income of 85,000 euros – the income limit of 100,000 euros is respected. The new construction (Efficiency House 40 with heat pump, without QNG seal) costs 520,000 euros including the plot. 70,000 euros of equity are available, so the financing requirement is 450,000 euros.

Without funding, the family would have to finance the full 450,000 euros at 3.8 percent – interest costs in the first year: around 17,100 euros. The KfW component therefore saves around 4,590 euros per year. Over the ten-year fixed interest period, the benefit sums up – slightly decreasing with ongoing principal repayment – to roughly 40,000 euros.

With a QNG seal and a KfW share of 220,000 euros, the savings would be even higher, though this is countered by certification and additional construction costs, which you should balance against each other in individual cases.

KfW 308 “Jung kauft Alt”: Funding for Existing Buildings

Since September 2024, the program “Home Ownership for Families – Acquisition of Existing Property” (KfW 308) has complemented family funding with the purchase of existing properties. Under the name “Jung kauft Alt” (KfW 308), the federal government specifically funds the acquisition of energy-inefficient existing buildings that are subsequently renovated. The idea: families can acquire home ownership more affordably, while at the same time the existing old building stock is modernized energetically without sealing new land.

KfW 308: Requirements and Conditions

• Household and income: The same rules apply as for program 300 – at least one minor child, no other residential property, owner-occupation with at least a 50 percent co-ownership share. The income limit for KfW 308 is also identical: 90,000 euros taxable income plus 10,000 euros per additional child, averaged over the penultimate and the year before the penultimate year.
• Property: Funding is provided for the purchase price (including land) of an existing property that falls into energy efficiency class F, G, or H according to a valid Energy Certificate according to the Buildings Energy Act (GEG). A property that has already been renovated with a good efficiency class is explicitly not eligible. Therefore, ask to see the energy certificate early on – it decides the eligibility for funding.
• Renovation obligation: Within 54 months (four and a half years) after loan approval, the building must be brought up to at least the Efficiency House 85 EE standard. Until October 2025, the stricter Efficiency House 70 EE was required; the reduction has made the program significantly more practical. An energy efficiency expert accompanies the renovation roadmap and verification.
• Application before purchase: The application must be submitted before concluding the notarial purchase contract. The income tax assessments must already be submitted at the time of application.

Loan amounts: current values and increase from August 2026

For KfW 308, the loan amount also depends on the number of children. As of August 3, 2026, KfW will significantly increase the maximum amounts based on an amended funding directive. The time of application is decisive, not the notary appointment – anyone who submits the application from August 3, 2026 automatically receives the new limits.

In addition, from August 2026, the funding conditions will be expanded to include the option of single energetic measures, making the renovation requirements more flexible. Check the details in the then updated KfW 308 leaflet before determining the scope of the renovation.

Interest rate for KfW 308

The interest rate for KfW 308 – like for program 300 – is significantly below the market level. Since the condition improvement in October 2025, effective interest rates for short terms start at a symbolic 0.01 percent; for long terms with a ten-year fixed interest period, they are around or partly below 1 percent (as of July 2026). You can find the daily updated values on the KfW program page for loan 308.

Annuity loans with various terms and a bullet loan are available as loan forms; here too, the KfW repayment calculator helps with installment planning. There is no repayment subsidy in program 308 itself – but there is one in renovation loan 261, which is typically combined with it.

Example Calculation KfW 308: Buying and Renovating an Old Building

Family B (two children, average taxable income of 78,000 euros) buys a terraced house from the 1960s, energy class G, for 320,000 euros. The renovation to Efficiency House 85 EE is calculated at 150,000 euros.

1. Purchase price financing: 125,000 euros via KfW 308 at around 0.9 percent effective (application before August 3, 2026; after that up to 160,000 euros would be possible), the remainder via a bank loan at 3.7 percent. Interest savings of the funding component in the first year: 125,000 € × (3.7 % − 0.9 %) = 3,500 euros; roughly 30,000 euros over ten years.
2. Renovation financing: For the renovation itself, the family combines the KfW 261 (“Residential Buildings – Loan”) – up to 150,000 euros per residential unit, also interest-subsidized and with a repayment subsidy, the amount of which depends on the reached Efficiency House level. The repayment subsidy reduces the remaining debt directly and does not have to be paid back.
3. Result: Instead of financing the full 470,000 euros entirely at the market interest rate, the family handles a significant portion via two promotional loans. The combined benefit of the interest subsidy and repayment subsidy quickly reaches the range of 40,000 to 60,000 euros, depending on the renovation standard.

Important: Calculate renovation costs conservatively and with a buffer. The obligation to reach the Efficiency House 85 EE within 54 months is binding – anyone who misses it risks the clawback of the interest subsidy.

Comparison between KfW 300 and KfW 308

Anyone building a new home or buying a new construction as an initial buyer and meeting the requirements uses program 300 – it is practically always the cheapest component on the market.

Anyone buying an existing property in need of renovation uses program 308 plus renovation funding. Using both programs for the same property is excluded.

Combining KfW 300 and 308 with other programs

In principle, the family programs can be combined with other funding resources, as long as the sum of all loans and grants does not exceed the eligible costs. In detail, however, important exclusions apply:

Can you combine KfW 300 and 297?

No. A combination of KfW 297 and 300 for the same project is excluded – both programs promote climate-friendly new construction and would double up. The same applies to the combination of KfW 298 and 300; program 298 is aimed at landlords anyway, not owner-occupiers. Anyone who meets the requirements for the family program is almost always better off with KfW 300 than with 297: lower interest rate and higher loan amount.

Combining KfW 124 and 300

Yes, that is possible. The KfW Home Ownership Program 124 (up to 100,000 euros, no income limit, but with a more market-oriented interest rate) can be combined with KfW 300 and tops up the promotional share of the overall financing. KfW itself mentions this combination as a typical example.

State development programs as well – such as low-interest loans from state development banks or municipal building land programs – are usually combinable; inquire about this with your state development bank or municipality.

Combining KfW 261 and 308

Yes – this combination is actually the rule: KfW 308 exclusively finances the purchase price, while KfW 261 finances the subsequent renovation to Efficiency House level including a repayment subsidy. On the other hand, a combination with the new construction programs 297, 298, and 300 as well as double funding of the same costs is excluded for 308. Anyone who has already received Baukindergeld for a child is also excluded for the same constellation.

Applying for KfW 300 and 308: Step by Step

You do not apply for either loan directly with KfW, but through an intermediary primary bank, savings bank (Sparkasse), Volksbank, or a financing broker. This is how it works:

1. Check requirements: Check the income limit using tax assessments, clarify the number of children and ownership conditions. Read the official leaflet for loan 300 or the leaflet for KfW 308 in the KfW download center beforehand – all conditions there are binding.
2. Involve energy efficiency experts: For new construction, the expert confirms the “Climate-Friendly Residential Building” or QNG standard and creates the Confirmation of Application (BzA). For existing property acquisition, they check the energy certificate and plan the renovation to Efficiency House 85 EE.
3. Submit application before project start: For KfW 300 before the start of construction work or before the purchase contract, for KfW 308 mandatorily before the notarial purchase contract. Planning and consulting services may take place beforehand, but excavation work and contracts may not.
4. Wait for approval, then start: Only start construction or purchase once you have the loan approval. The interest rate is fixed with the approval.
5. Submit proof: After completion or renovation, you submit the Confirmation after Implementation (BnD) via your bank.

Allow two to four weeks of lead time for bank meetings. Since the funding comes from the federal budget and budgets are generally limited, early application is recommended – even though both programs are currently available regularly.

Frequently Asked Questions about KfW 300 and KfW 308

What is KfW 300 in one sentence?

KfW 300 is a low-interest promotional loan of up to 270,000 euros for families with minor children and limited income who are building a new climate-friendly home or buying one as an initial purchaser.

Is KfW 300 stopped – and how long will the program still exist?

No, KfW 300 has not been stopped. The confusion usually stems from the “Climate-Friendly New Construction” program (297/298), which was temporarily suspended in December 2023 due to exhausted budget funds. The family program continued continuously and has since been improved several times – most recently through the interest rate cut in October 2025 and the increase in 308 loan amounts as of August 2026.

An end date has not been announced; however, since the interest subsidy is financed from federal funds, availability basically depends on the federal budget. Anyone who meets the requirements should therefore not put off applying.

Is there a repayment subsidy for KfW 300?

No. Both family programs work exclusively through the subsidized interest rate. Repayment subsidies are available in renovation funding, such as KfW 261, which can be combined with 308.

What experiences are there with KfW 300 and 308?

Experiences from consulting practice can be summarized as follows: The interest rate advantage is real and substantial – often 2 to 3 percentage points below the market level. In the new construction program, critical views are directed at the high requirements (Efficiency House 40 plus life cycle assessment) that drive up construction costs, as well as the interest rate fixed period limited to 10 years, which makes follow-up financing at the then-applicable market interest rate necessary.

In program 308, the renovation obligation is considered the biggest hurdle – however, since the reduction to Efficiency House 85 EE and with the higher loan amounts from August 2026, the program has become significantly more attractive. Bottom line: anyone who is eligible for funding throws money away without these programs.

Where can I find the leaflet, conditions, and a calculator?

KfW provides all binding documents – leaflets, the daily updated conditions overview, and the “Annex to the leaflets” with the technical minimum requirements – on the program pages for loan 300 and loan 308.

You can calculate monthly installments and remaining debt using the official KfW Repayment Calculator. For the question of whether QNG or a specific term is worth it, an independent financing and energy consultation is additionally recommended.