Furnished floor plans are fundamental to real estate visualization, interior design, and architectural workflows. However, progress in automatic furniture arrangement has been limited by the lack of real, professionally designed floor-plan datasets with object-level furniture annotations. To address this gap, we introduce AntPlan-270, a curated dataset of 270 architectural floor plans with per-room furniture bounding box annotations across ten residential room categories. Building on this dataset, we present Architect-Ant, an editable automatic furnishing framework powered by a fine-tuned vision-language model. Furniture layouts are represented using a compact, coordinate-based domain-specific language (DSL) that encodes object categories and placements relative to the room geometry. To improve spatial reasoning, we generate procedural reasoning traces that capture architectural constraints such as wall alignment, door and window clearance, circulation, fixture compatibility, and room-specific furniture inventories, and use them to supervise fine-tuning of the model. We then apply preference optimization over candidate object placements to further refine layout quality. The generated DSL can be rasterized into semantic masks and used to condition a Flux-based LoRA renderer, producing realistic blueprint-style furnished floor-plan images while preserving the editable symbolic layout. Experiments on layout furnishing show that Architect-Ant produces geometrically valid and functionally plausible layouts, and suggest a scalable path for furnishing larger structure-only floor-plan datasets.

翻译：带家具的平面图是房地产可视化、室内设计和建筑工作流程的基础。然而，由于缺乏带有物体级家具标注的真实专业设计平面图数据集，自动家具布置领域的进展一直受限。为填补这一空白，我们提出了AntPlan-270，一个包含270个建筑平面图的精选数据集，涵盖十个住宅房间类别，并为每个房间提供了家具边界框标注。基于该数据集，我们提出了Architect-Ant，一个由微调后的视觉-语言模型驱动的可编辑自动家具布置框架。家具布局采用一种紧凑的、基于坐标的领域特定语言（DSL）表示，该语言将物体类别及其相对于房间几何形状的放置位置进行编码。为提升空间推理能力，我们生成了过程性推理轨迹，用于捕捉墙面对齐、门与窗户的净空、通行流线、设施兼容性以及房间专属家具清单等建筑约束，并利用这些轨迹来监督模型的微调。随后，我们通过对候选物体位置进行偏好优化，以进一步改善布局质量。生成的DSL可光栅化为语义掩码，并用于条件化基于Flux的LoRA渲染器，从而在保留可编辑符号化布局的同时，生成逼真的蓝图风格带家具平面图图像。针对布局布置的实验表明，Architect-Ant可生成几何有效且功能合理的布局，并为填充更大规模的仅有结构的平面图数据集提供了一条可扩展的路径。