In the field of software engineering, several empirical methods have been developed to model software projects before they are undertaken to provide an estimate of required effort, development time and cost. In the case of Web applications, this process is complicated by their complexity, multitiered nature, extensive use of noncode artifacts such as multimedia and often short time-scales. In this paper we describe a simple, highly adaptable model using COSMIC full function points for application size measurement and design patterns as a measurement reference. Rather than a true derived model the aim is to provide a procedural framework for expert judgement which guides the practitioner through the estimation process, seeking to limit or mitigate variance in their judgement through algorithmic or statistical techniques. This hybrid has so far proven as accurate as expert judgement while remaining capable of application by a relatively inexperienced estimator.